After a roast, fish and chips is the nation’s most popular dish. And more than any other, it shows how subjective perfection is. Fish and chips makes foodies of us all; everyone has their preferences. Cod, haddock, or plaice? Chunky, soggy chips the size of your fingers, or thinner, crispier ones? Does it taste better from newspaper? The debate doesn’t stop there: whether it’s accompanied by ketchup, mayonnaise, gravy or curry sauce probably depends on where you grew up, but for me, fish and chips have to be doused in Sarson’s malt vinegar.

For some people, fish and chips is a seaside memory — gulls squawking as they hover in wait for leftovers; the sea’s briny tang mixing with the salt of the chips. But I grew up in London, so I have a more urban take. On the way home from work, Dad would pick up fish and chips from Micky’s Fish Bar in Norfolk Place. On my birthday one year, I was given the money and allowed to get them myself. I can vividly remember the brisk fizzing noise of the fryer, the wonky menu board, the yellow glow emanating from the glass-fronted warmers on the counter. I took the fish and chips home and we ate them from the paper.

I always loved digging down to the bottom for the smaller bits that had gradually settled there, the chunky shards of batter that had broken off from the fish. That marvellous mix of textures has stayed with me: crisp batter giving way to fat, smooth, moist flakes of fish; the chips’ crunchy exterior contrasting with a light fluffy centre. It was in seeking to re-create them that I experimented until I came up with my version of fish-and-chip perfection.

Cod, plaice or haddock and maris piper potatoes are the traditional raw ingredients for fish and chips, yet after consultation with David Blagden, of James Knight of Mayfair, fishmongers to the Queen, and Claire Harrison of the potato specialists MBMG, I decided to fry up nine potato varieties and six different fish. And I came up with clear winners for my recipe: turbot, and arran victory potatoes. Arran victory has the perfect balance of flavour and texture when cooked as a chip: the glass-like exterior crunching apart readily, the interior soft and delicately fluffy. It’s this contrast that makes a great chip — the mix of two very different textures giving the mouth a sublime surprise. Turbot has a pleasant texture and a fuller flavour than, say, cod and its combination of large flakes and moist, succulent, flavoursome flesh is the perfect contrast to a crunchy, textured batter. It all goes to produce a more complex and delicious fried fish than your average chippy fare.

A few pointers on buying your ingredients: as with meat, the cut of fish you choose is important. Muscle is crucial to the flavour, so whether you are buying a flat fish, such as plaice, a flaky fish, such as haddock or a round fish such as john dory, you should try to get a male fish, as they develop more muscle while swimming around, trying to impress the females, and don’t waste energy on reproduction. Geography will also affect the look and taste of fish, so ask where your fish comes from — different fish like different types of water and a good fishmonger will know this.

With potatoes, high dry-matter content is the key to chips with a good flavour and texture, so avoid waxy potatoes with low dry matter — they fry too dark and the inside comes out almost wet, which means it will stick to your tongue. A tip worth knowing: potatoes with a higher dry-matter content will sink if you put them in a bucket of water, those with less dry matter will float. And be aware that potatoes for chips need to be stored at 7–9C, to avoid the starch turning to sugar and giving the potato a dark fry colour.

Before you start

No matter how good your fish, it can be ruined by bad batter. Batter has to insulate the fish from the high heat of the fryer and also turn a crunchy, crusty brown in the time it takes for the fish to cook. So it was vital to develop a batter that suited the thickness of an average turbot fillet. A water-based batter takes a long time to go brown, because all the water has to evaporate before it will cook. Vodka is more volatile, so it evaporates much more quickly. It has the added benefit of not developing the gluten in the flour the way water does, which means you get a crisper crust. Using lager and a soda siphon enhances the batter’s crunchiness by introducing lots of bubbles that give it a marvellous lightness.

Good chips also depend on the removal of liquid. Allowing the chips to cool right down between each stage of cooking gets rid of much of the moisture that would otherwise escape from the chip as steam during frying, causing a soggy exterior. Instead, you’ll have a crisp crust and a fluffy centre — the perfect chip. And if you use an atomiser to spray the chips — and the room — with the juice from a jar of pickled onions, the smell will be a fantastic nostalgia trigger, conjuring up memories of your favourite fish-and-chip shop.

Special equipment

Soda siphon (plus CO₂ charges), digital probe, deep-fat fryer, atomiser (optional).

Timing

Making the batter is easy, but it needs to chill for at least half an hour in the fridge, after which, in order to keep the bubbles in, speed is the name of the game.

Cooking the chips is a three-stage process; it’s not complicated, but it takes a little longer, because the chips have to cool down before and after the first frying. Preparing the chips to this point and leaving them overnight in the fridge will make a fish-and- chip supper a quick and simple affair.

THE RECIPES

PERFECT FISH AND CHIPS

Ideally, get a whole turbot weighing 2.5kg and fillet it yourself or get the fishmonger to do it. If you can’t, get four individual ones.

Serves 4

For the fish

200g plain flour
200g Doves Farm white rice flour, plus extra for dusting (from all good supermarkets or www.goodnessdirect.co.uk)
1 tsp baking powder
1 tbsp honey
300ml vodka
300ml lager (Kronenbourg 1664 works well)
2-3 litres groundnut (peanut) oil
4 large turbot fillets, 2–3cm thick
Table salt and freshly ground black pepper

1 Tip the plain flour, rice flour and baking powder into a bowl. Put the honey and vodka into a jug, stir, then add to the flour to create a batter mix. Open the lager and stir it into the batter until just combined. It doesn’t matter if the consistency is a little lumpy. The most important thing is to open the lager just before stirring and transferring to the siphon (see step 2), to retain as many bubbles as possible.

2 Transfer the batter to a jug, then pour it into a soda siphon. Charge the siphon with three CO₂ charges and put it in the fridge for a minimum of 30 minutes.

3 In a large pan or casserole, put enough groundnut oil to cover the fish. Heat it to 220C/425F, using the digital probe to check the temperature. (It’s best not to use a deep- fat fryer for this, because the temperature fluctuates too much and has trouble reaching 220C/425F.

4 Rinse the turbot fillets and dry them with paper towels. Season well, then dust with rice flour — this ensures the batter sticks to the fillets. Shake off any excess flour.

5 Remove the siphon from the fridge. Shake it vigorously, then squirt enough batter to cover a fillet into a medium-sized bowl. (Don’t squirt out too much — the batter begins to lose its bubbles as soon as it leaves the siphon.) Dip the fillet into the foamy batter. When it is completely coated, lower the fillet head first into the oil holding it by the narrow tail end to avoid splashes.

6 As the fish fries, drizzle a little extra batter over it, to give a lovely crusty exterior. When it has turned a light-golden brown, which will take 1-2 minutes, turn the fillet over and drizzle more batter on that side.

7 Let the fish cook for another minute or so, until it has coloured to a deeper golden brown, then remove it from the oil. Use the digital probe to check it is cooked: insert the probe into the thickest part of the fish — once it reads 40C/105F, the fillet should be set aside. The residual heat will cook it to a temperature of 45C/113F.

8 Repeat the above process with the remaining fillets.

For the chips

1.2kg arran victory or maris piper potatoes
2–3 litres groundnut (peanut) oil
Table salt and sea salt

1 Wash and peel the potatoes, then cut them into chips about 1.5cm thick. (Don’t worry too much about making them all the same size: the variation will give a greater range of textures.) As soon as the chips are cut, place them in a bowl under cold running water for 2-3 minutes, to rinse off some of the starch, then drain.

2 Bring a large pan or casserole of salted water to the boil (adding 10g salt per litre of water), add the chips, bring back to the boil and then simmer until the chips have almost broken up (it’s the fissures that form as the potato breaks up that trap the fat, creating a crunchy crust). It is important to make sure the simmer is gentle, so that the potatoes don’t start to fall apart before they have cooked through.

3 Using a slotted spoon, carefully lift the potatoes out of the water and place on a cake rack. Leave to cool, then put in the fridge until cold. (The dry air of the fridge makes a good environment in which to remove excess moisture from the chips via evaporation.)

4 Pour enough groundnut oil to cover the chips into a deep-fat fryer and heat it to 130C/250F. Plunge in the chips and allow them to cook until they take on a dry appearance and are slightly coloured.

5 Remove the chips and drain off the excess fat. Place them on a cake rack and allow to cool, then return to the fridge until cold.

6 Reheat the groundnut oil to 190C/375F. Plunge in the chips and cook until golden brown. This will take 8-10 minutes.

7 Drain the chips, season well with a mixture of table and sea salt, then pile next to the fish fillets.

To serve

1 jar of onions pickled in malt or white-wine vinegar (whichever is the more evocative)
1 atomiser

Decant the pickling juice from the jar of pickled onions into the atomiser and squirt it around the room or on the fish and chips.

TARTARE SAUCE

3-4 small shallots, peeled and finely chopped
1 egg, hard boiled
3 tbsp gherkins, finely diced
3 tbsp capers, chopped
20 tarragon leaves, finely chopped
4 tbsp parsley leaves, finely chopped
4 tbsp chervil, finely chopped
4 tbsp chives, finely chopped
150ml mayonnaise
30ml whipped cream

Place the shallots in boiling water until translucent — this should take about 30 seconds. Remove from the boiling water and place immediately in a bowl of iced water. Remove from the iced water, then set aside.

Finely dice the egg white, then place in a bowl with the gherkins, capers and prepared shallots. Pass the egg yolk through a sieve, then add it to the bowl. Next, add the herbs and mayonnaise, then fold in the whipped cream.

Mushy peas

Serves 4-6

475g frozen peas (I like Birds Eye)
65g butter
6 mint leaves
Salt and pepper, to taste

1 Defrost the frozen peas in a large pot filled with cool water — this should take a only few minutes. Strain, shaking off as much excess water as possible.

2 Reserve about one-fifth of the peas.Place the remaining peas into a sauté pan, along with the butter and 50ml water. Cook over a medium heat until all the water has evaporated and the peas are cooked through. If your water is very hard, it would be best to buy some bottled water (or, even better, de-ionized car-battery water) to use when cooking the peas, as this will help to keep their colour bright green.

3 Place the cooked peas into a blender (or use a stick blender) and purée. While blending, adjust the taste by adding the mint leaves and the salt and pepper.

4 Fold in the reserved peas and serve.

A short history of fish and chips

This classic English dish came from a tradition of street food that was already growing in the 19th century with the hot-pie shops of Victorian England. Fried fish got a mention by Dickens in Oliver Twist (published in 1837), though it was then sold with a hunk of bread or a baked potato.

The birthplace of fish and chips is unidentifiable: Lancashire, London and Dundee have all put forward a claim. The combination of fresh fish and a hungry working class makes it likely that the dish developed in the northern ports. In the south, the alliance of fish and potato could well have been forged in the East End of London, where the close confines of the tenements meant the fried-fish tradition of Jewish immigrants would have come into contact with the potato-based diet of the Irish.

Three factors increased the dish’s popularity: manufactured ice meant fishermen could travel further and catch more, preserving their haul in ice; steam trawlers greatly increased the range of fishing opportunity; and railways meant distribution could reach inland areas.

Both the French and the Belgians claim they invented the chip, or fry, in the 19th century. Fries were certainly popular in both countries by the 1830s, and had reached Britain before the turn of the century.

The status of the chip as an international food is the result of the cultural shake-up that occurred during the first world war. American soldiers stationed in France (and Belgium) developed a taste for chips that they took back home with them. It was then just a short step to world domination. The humble chip is the main reason why potatoes are still up there among the world’s top crops.

A good catch

Fish are one of our most ancient food sources. Archeologists have found huge piles of oyster and mussel shells — evidence of fish feasts — dating back 300,000 years. This relentless plundering of the oceans has come at a cost. Many once-common fish are under threat; our seas and rivers are all but exhausted; and if we don’t adopt a responsible attitude and change how we eat, we’re going to run out of fish. This would be a disaster for our diet and health, and for the world’s ecosystem and biodiversity.

But there are ways to eat fish responsibly. The Marine Stewardship Council (www.msc.org) inspects fisheries and certifies those that comply with sustainable fishing practices. Find out if your purchases are from MSC-approved sources.

If the fish is farmed rather than caught, ensure it’s organic and accredited by the Soil Association. (Fish farms exact their own damage on the environment, so it’s important that these are also run responsibly.)

Find out which fish are abundant in British waters and try them out as an alternative to those that have been air-freighted thousands of miles. The Marine Conservation Society Good Fish Guide is a great starting point on what to buy (from www.mcsuk.org), as is www.fishonline.org, which has a search facility so you can check whether a fish is on the endangered list.

Fish sources

Find a good local fishmonger and make friends with him. He should be able to tell you which fish to choose and where it comes from. His advice will be invaluable. You will learn a lot that will help you in the kitchen.

Heston gets his fish from James Knight of Mayfair in London (020 7221 6177), fishmonger to the royal family, no less. But if you can’t buy from them, here are some other good suppliers:

The Fish Society, Surrey (0800 279 3474, www.thefishsociety.co.uk). An enormous selection of about 200 varieties of seafood available by mail order. The website has lots of recipes to inspire.

Cape Clear, W6 (020 7751 1609). Line-caught fish delivered daily, mostly from Dorset, Devon and Cornwall. Recommended by Heston.

Fowey Fish, Cornwall (01726 832422, www.foweyfish.com). Family-run business selling all manner of fresh fish, including turbot, by mail order.

Martins Seafresh, Cornwall (0800 027 2066, www.martins-seafresh.co.uk). An online company that sells a huge variety by mail order. Recommended by Delia Smith.

Steve Hatt, N1 (020 7226 3963). Probably the best fishmonger in London. Nigel Slater has been spotted patiently queuing along with everyone else. Good variety of very fresh produce and staff who really know their stuff.

Taste, Barrow Gurney, near Bristol (01275 474300). A fabulous seafood supplier, with a delicatessen and butchery, too. A favourite with Heston.

The Whitby Catch, North Yorkshire (01947 601313, www.thewhitbycatch.co.uk). This shop and mail-order business is across the road from Whitby fish market, and again has a vast selection to choose from.

And for the chips

MBMG (www.potatolovers.co.uk) will recommend different varieties to try and can give you local stockists.

It also sells by mail order, but only in very large quantities.

Extracted and adapted from In Search of Perfection by Heston Blumenthal (Bloomsbury £20). To order for £17.99 (inc p&p), call The Sunday Times Books First on 0870 165 8585