My version of a Spanish Tortilla, using carb-lowered Potatoes – and Carb-lowered Potato Ratatouille. Two ‘From Tunnel to Table’ recipes for midsummer – using a process known as ‘Retrogradation’.

My version of a Spanish Tortilla with carb-lowered potatoes and my carb-lowered Potato Ratatouille

My version of a Spanish Tortilla with carb-lowered potatoes and my carb-lowered Potato Ratatouille

The two delicious and useful recipes here both use pre-cooked and chilled potatoes, which are subsequently cooked again. This very easy cooking process is known as ‘Retrogradation’ – and can reduce the carbohydrate content of recipes by as much as 50%.  I call potatoes treated in this way ‘carb-lowered potatoes’ – as I think that’s a bit less sciencey-sounding than Retrogradation! I explain in brief the science behind the process and it’s benefits further down, below the recipes.

These are also both gut-friendly recipes. As it was the first-ever ‘World Microbiome Day’ last week on 27th June, I also wanted to do something which would combine looking after our vital resident gut microbes too.  I’m very keen on looking after our gut as it’s the basic foundation of both our physical and mental health. This is something I first discovered 40 years ago when my daughter was born with many allergies – which you will already know if you’ve read my instructions for kefir making here: –  It’s something which I’ve had an abiding interest in since then and there’s a lot of very exciting research going on now, which is constantly discovering new things about how our gut residents affect our health and the benefits of looking after them as well as we can, by eating organic whole foods – not highly refined, processed, chemical additive-filled foods.

There are no step by step pictures with these two recipes as they are very easy.

(As always – all of the ingredients in my recipes are organic and easily available in most supermarkets and other shops. Organic foods are proven to be at least 60% higher in beneficial omega 3 fats and also in phytonutrients. They are also grown in a healthy, microbially-rich, living soil with no synthetic pesticides or fertilisers used in their production).

From my midsummer polytunnel I used: 

Onions, garlic, potatoes, courgettes, tomatoes, basil and parsley, and also organic eggs from our hens that eat lots of produce from the tunnels. The tortilla was served with salads from the garden.

The first recipe is my version of a classic Spanish tortilla – using onions, potatoes and garlic from the tunnel and eggs from our hens. It’s very similar to the frittatas I’ve made before – but using potatoes in the recipe as well, along with bacon and cheese which would not normally be in a tortilla, but which increase the healthy protein content. This recipe is great for using up any small bits of leftovers of anything else too.

It’s fantastic summer picnic food as it’s best eaten cold or room temperature. It’s also good for summer lunches, lunchboxes, or suppers served with a salad. It’s very satisfying and filling.

The second recipe is my carb-lowered potato ratatouille, which is basically a classic stewed ratatouille, but with cooked and chilled potatoes added just before the end of cooking which make it more substantial. It’s really useful to have on standby in the fridge for quick meals and is nice either served chilled, at room temperature, or re-heated.

Recipe 1. My version of Spanish Tortilla, using carb-lowered potatoes, with smoked bacon.

 The Violetta potatoes look like jewels inside the cut Tortilla
The Violetta potatoes look like jewels inside the cut Tortilla

Serves 4 for supper or lunch with a side salad, or 8 as part of a Tapas or finger buffet

(You will need a non-stick ceramic pan to cook this – which can be put under the grill with the tortilla still in it. It won’t slide out onto another dish for grilling as it’s too delicate when half-cooked. If you don’t have a pan without a handle – then protect the handle of the frying pan with some aluminium foil to stop it burning and leave the grill door open.)


Olive oil & butter for frying

1 Packet of smoked bacon rashers – I used 4/5 rashers of M&S organic. (6 in pack – I snaffled the other!) Any other organic bacon – either streaky or back rashers will do fine.

225g/8oz firm waxy potatoes, cooked, chilled overnight and diced. (varieties such as Nicola, Charlotte or Vivaldi are good and easily avaiable – but any firm potatoes will do. I used the purple potato Violetta in this recipe as they are waxy, look very pretty, and are also good for our gut as they contain high levels of anthocyanin phytonutrients)

150g/5oz red onions, thinly sliced (I always use red onions as they are much higher in polyphenol antioxidants and quercitin than white onions)

1 large or 2 small cloves chopped/minced garlic

8 med/large organic eggs (I always use organic – all other hens are fed on rations containing genetically-modified soy beans and grains, which are sprayed with many pesticides)

100g/4oz Organic Cheddar cheese, grated

1 heaped tablespoon chopped parsley

Freshly-grated black pepper (it must be organic and freshly grated, as that retains it’s many nutritional benefits and great flavour)


1. Fry the bacon rashers until browned and crispy. Chop into pieces (with scissors is easy) Set aside to cool and cover.

2. Fry the thinly-sliced onions in the remaining fat, adding a little more if necessary to prevent sticking, covering for first 5 mins. They will pick up all the flavours from the pan Then take off lid and fry, stirring occasionally until limp and cooked. Cool and set aside.

3. Whisk the eggs lightly in a large bowl.

4. Add a few good grinds of organic black pepper. This doesn’t need salt because the bacon is usually quite salty.

5. Add all the other cooled ingredients to the beaten eggs and gently mix well, being careful not to break up the potatoes.

6. Put a knob of butter and a small glug of olive oil into a large, ceramic, non-stick frying pan and when it’s hot and foaming but not burning, pour in the tortilla ingredients as evenly as possible, turning down to the lowest setting immediately to avoid the bottom burning

7. Cook gently until the top is almost set buts is still a little runny in the middle. Put under a hot grill just to set but don’t brown the top too much or it may be tough

8. Leave to cool in the pan as it comes out more easily when it’s well-cooled. Best serve either cooled at room temperature or chilled. Keeps for several days in the fridge, but doesn’t freeze.

Recipe 2. Carb-lowered Potato Ratatouille

 The carb-lowered Potato Ratatouille goes well with any meat of fish
The carb-lowered Potato Ratatouille goes well with any meat of fish

Serves 4 as a side dish with a main course and goes perfectly with any kind of meat or fish. It keeps very well in the fridge and in fact gets even better after a couple of days when the flavours have blended and married a bit more.


450g/1lb of potatoes, cooked and chilled overnight, then diced.

50ml/2floz olive oil for frying.

1 large or 2 medium red onions, sliced

3 cloves of garlic, minced or finely chopped

1 large, any colour sweet pepper cored and sliced – we prefer red or orange, but green’s good too

400g/14oz fresh tomatoes blitzed in blender (don’t remove the skin – doing that wastes important phytonutrient Lycopene and gut-friendly fibre)

2 medium courgettes, sliced (roughly 8-10oz or 280g each but more or less not critical – don’t waste any!)

Small scrunched handful of basil leaves chopped or 1 tablespoon of chopped frozen basil

Salt & black pepper to taste.


1. Heat the oil in a large frying pan or saucepan, add the onion and cook until limp

2. Add the garlic and sliced pepper, and cook for another 5-10 minutes, until the pepper starts to soften slightly

3. Add the blitzed or tinned tomatoes, courgettes, basil, pepper and a small pinch of salt (you can add more salt to taste at the end of cooking if needed)

4. Simmer all gently for about 15-20 minutes, then add the cold potato and simmer for another 10 minutes

5. Serve hot or room temperature. Nice as a side dish with anything or with some crusty, carb-lowered, frozen and re-heated bread! Can also be turned into a vegan/vegetarian main dish by adding some cooked lentils or beans

What is Retrogradation? It’s just cooking – but differently!  (Here’s the easy Science Bit!)


Retrogradation is a process which is a really useful way to prepare many starchy carbohydrate-rich ingredients for recipes, which is especially important if you are trying to reduce the amount of quickly-digested carbohydrates which you eat, and also scale up the gut-healthy fibre content of your diet. The short explanation is that basically – you pre-cook foods containing starchy carbohydrates, chill them for at least 8 hours and then reheat them. When you do this, some of the starch molecules rearrange themselves and any fats or oils with which they are cooked cling to them – making the starch much harder to digest by turning them into what’s known as ‘resistant-starch’ and effectively lowering their available carbohydrate content.


Although retrogradation is a well-know term used in commercial baking – this is an area of science that so far hasn’t been investigated that thoroughly yet as far as our daily diet goes. But what is known about it so far appears to be very exciting!  From a nutritional point of view, it’s a double-whammy – almost like having your cake and eating it! The process is not only able to reduce the effects of many starchy carbs – but it also encourages our good gut bacteria!  That’s great news – if like us you still want to be able to enjoy a few carbs now and again – but would like to painlessly be able to reduce their effects on your body. Many of us are becoming much more aware that easily-digested, highly refined carbs and high carbohydrate foods like potatoes can cause a very rapid spike in blood sugar, because our bodies treat them in exactly the same way as they would glucose or sugar. By eating high-carbohydrate foods too often, this constant rise in blood sugar can eventually cause insulin resistance – potentially leading to Type 2 diabetes, with a lot of very nasty complications. So what person wouldn’t want to easily reduce their carbs in order to be healthier? By using this simple retrogradation process on starchy-carbohydrate foods like potatoes, pasta, bread and grains – you can reduce their carbohydrate content by roughly 50% in a totally painless way, and they’re still just as delicious as it has no effect on their taste!

The process of retrogradation turns some of the starch into what is know as ‘resistant starch – or RS’ – which literally means that it resists digestion in the small intestine (the part of our gastrointestinal tract where most of the absorption of food takes place). This can reduce how much sugar our body absorbs from the food by as much as 50%. The undigested starch then becomes a kind of fibre, which continues it’s journey through our digestive tract into our colon – where it encourages the healthy growth of more beneficial gut microbes, which love to feed on resistant starch. As a by-product – when those gut microbes feed on RS, they then produce compounds which are very beneficial both for our gut lining and for our general health – preventing colon cancer and other diseases. Gut microbiome scientists such as Professor John Cryan, who recently published a fascinating book – ‘The Psychobiotic Revolution’ in conjunction with Prof Ted Dinan and science journalist Scott Anderson, say that the more of this resistant-starch we can eat – the better it is for our health, and that we currently eat far too little compared to our ancestors. They also say that there is evidence that the lack of RS is one of the major causes of many modern, non-infectious, ‘lifestyle’ diseases such as Type 2 Diabetes and colon cancer.


The Retrogradation process sounds very scientific – but don’t think it’s difficult!  In fact it actually couldn’t be easier. It’s just cooking – but differently! I’d actually been doing it for many years without even realising it! Having a very busy life but still wanting to eat real food – I’ve always looked for ways to save time when preparing meals for the family – and it’s great time-saver! I’ve always cooked a few day’s supply of potatoes to keep in the fridge, as it doesn’t just save time but also saves energy cooking a big batch together. Ready-mashed potatoes, parsnip, swede and carrots are also very useful to have in the freezer, to be taken out and thawed ahead in the fridge on busy days when I know I won’t have much time in the evening. It’s far quicker to get meals if some of the ingredients are pre-cooked and can be heated up in 5 minutes.

I find it also helps to prevent food waste and saves money. If I only have a tiny amount pasta left I freeze it with a few drops of olive oils sprinkled on to stop it sticking together (which also helps to produce RS) – then when I have lots of bits they all go straight into a pot of boiling water for mixed pasta, ready in 2 minutes! If I have any mashed potato left after a meal, I always freeze it too, instead of throwing it away as many people might. Then I thaw out various bits of mashed potato when I have enough, and heat them all up in a saucepan, beating well to re-combine them again as mash can tend to become watery and separate slightly on freezing. Doing this makes it creamy again and just like freshly mashed potato. When I have ready-cooked, whole potatoes chilled in the fridge – I often just heat one up under the grill with a bit of grated cheese on top for a quick, tasty supper! Pre-cooked chilled potatoes also make the best lazy but healthy chips fried in a bit of olive oil for a 5 minute egg and chips (one of my favourite meals)! Or for the best roasties ever in half the time – just throw the pre-cooked potatoes into a hot pan of olive oil – stir them around to coat, put them in a very hot oven and in 20 mins they’re crisply ready to go!

I never boil potatoes but always steam them to pre-cook, in their skins, as this keeps them firm and preserves more of their nutrients – especially if they are the purple, antioxidant-rich, high-anthocyanin potatoes which I grow many varieties of. Otherwise they can lose a lot of their valuable phytonutrients into the cooking water – which ends up the colour of methylated spirits! I then cool and chill them overnight in the fridge for 8 hours, or for even up to a week. Then they’re ready to use anytime as an ingredient in any recipe where they will be cooked again. Simple!

How to eat the healthiest diet is something I’ve studied for well over 40 years since I first became interested in it after my daughter was born with her allergies. 
That’s when I started growing organic food too.  The official advice has changed many times over the years. Don’t eat fat – do eat fat etc – but I have never followed any of it, or eaten any ready-made processed foods like margarine. Not just because organic ones weren’t available anyway years ago, but also because nothing has ever changed my belief that first and foremost – the organic food that we evolved to eat is best for us – and I stick to that above all else. If it doesn’t exist in Nature – then basically we shouldn’t eat it. It’s quite simple. I believe that there is far more involved in keeping our metabolism working as efficiently as possible than can be solved by simply not eating sugar. If we have a healthy gut microbiome and are not diabetic – there is no harm in eating a few starchy carbs occasionally as long as we don’t over do them, if they are organic and are not contained in processed junk foods. And if we can reduce their effect on our bodies by using the retrogradation process and at the same time also improve our levels of beneficial gut bacteria – then that’s all to the good.


We still enjoy some grains, rice or pasta here from time to time – but without exception they are ALWAYS ORGANIC AND WHOLEGRAIN and I always lower the carbohydrate content of them and up the RS content by using this process. Many people prefer cooking with white flour, but when you get used to eating things made with wholegrain flour – you’ll find that wholegrain is not just far more nutritious and has more fibre – but it also has a lot more flavour. I really hate anything made with white flour – it tastes revolting, doesn’t satisfy you for very long as it raises blood sugar very quickly – and then you get the low sugar crash and feel awful afterwards!  We find that the best way to not feel hungry and deprived is just to eat more fibre by eating lots of green veg, salads, nuts seeds and other high-fibre foods, and lower carbohydrate whole fruits like tomatoes and peppers for instance – including their skins which contain a lot of beneficial phytochemicals. We don’t eat cake for treats here – our treats are the delicious fruits like berries and peaches that I grow.

The Retrogradation process can be used for many other carbohydrate containing foods, like pasta, rice and bread. We don’t eat very much bread here – but whenever I make a wholegrain loaf, I always slice and freeze it so that it stays fresh. This has the same effect of lowering the carbs and increasing the RS content, if you then use it straight from frozen for toast. Altogether – I think retrogradation is another pretty useful tool to have in our cook’s repertoire for a great many reasons!


If you are diabetic or pre-diabetic, then you need to reduce your carbohydrate consumption as much as possible. And it is possible – we’ve done it here without feeling deprived or keeling over from lack of glucose! We went on a strict LCHF (low carb high fat) diet for a while and I lost 2 stone easily – while my 6 ft 4 ins son lost 4 stones! The reason we went low-carb was to lose weight because after both my son and I had separate serious accidents 5 years ago which rendered us both immobile for a while – we had put on weight.

The biggest reason I personally put on the weight was because I refused to take any gut-damaging, anti-inflammatory medicines after I smashed my shoulder into 7 pieces! Having taken them 35 years ago after cervical spine surgery – I was keenly aware of their effect on our gut, as I developed a stomach ulcer from taking them at the time, which I later cured myself of without taking any pharmaceutical medicines. So after my shoulder injury 5 years ago – I instead relied on my wonderfully anti-inflammatory kefir with only occasional paracetamol – rather than the codeine which I was prescribed. To buffer the paracetamol whenever I took it – I ate bananas or bread – both high in carbs admittedly, and a problem when I could barely move, let alone exercise – but at least they effectively prevented damage to my gut!  Doctors are now amazed how well my shoulder has recovered, but if I had followed their advice – it would have been a downward spiral of more meds and then even more meds to counteract the effects of those etc. etc. and so on ad infinitum!

My son was also confined to a wheelchair for a while, and then on crutches – so was galvanised to lose weight not only because it would be beneficial for the healing of his multiple fractures and the brain haemorrhage which he sustained in his accident. He was also truly horrified by the sobering sight of the diabetic amputees in the orthopaedic ward where he spent some weeks recuperating after the major surgery which reconstructed his pelvis. It really made him think. It was awful to see those poor people whose suffering could have been prevented if they had been given the right advice to reduce their sugar intake either of junk food, carbs, pure sugar, or alcohol etc. Neither of us were pre-diabetic luckily though, we have both always exercised a lot and I have never had high blood pressure in my life. (Except for the time when both my lovely woman doctor and I collapsed into peals of laughter at a comment I made about the rather nice gynaecologist I had just visited! I won’t enlighten you about that! Luckily the temporary spike in blood pressure brought on by our fits of laughter rapidly went back to normal!)

(Please note.
 I really enjoy sharing my original ideas and 40 years experience of growing and cooking my own organic food with you. It’s most satisfying and naturally also very complimentary if others find “inspiration” in my work……But if you do happen to copy any of my material, or repeat it in any way online – I would appreciate it very much if you would please mention that it originally came from me. It’s the result of many years of hard work and hard-won experience. Thank you.)

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