A chef has caused a stir among food enthusiasts after she added a controversial ingredient to make the most famous fish and chips. Sophie Nahmad from recipe box service Gousto claimed that adding one ingredient to fish and chips can make it the “most delicious”.

This distinctive and polarising ingredient has been a household staple for years, though its use in batter recipes remains largely unexplored. However, Sophie is a firm believer in its potential, revealing Marmite, the iconic British yeast extract, as her secret weapon for enhancing both flavour and texture. She said: "Marmite adds a subtle, savoury depth to the batter that complements the fish beautifully. It’s not overpowering, but it adds a rich umami flavour that’s truly delicious.”

According to the food expert, Marmite also helps to improve the batter's texture. The yeast extract helps achieve a crispier, more golden crust. She said: "The key to great fish and chips is in the crunch. Marmite helps create a batter that fries up perfectly every time."

Preheat the oven to 220°C/ 200°C (fan)/ gas 7 and boil a full kettle

Peel the potatoes and chop them into chunky chips, then add them to a pot with plenty of boiled water and a generous pinch of salt and bring to the boil over a high heat

Once boiling, reduce the heat to medium and cook for 6-8 min or until slightly softened.

Meanwhile, add 1 tbsp vegetable oil to a deep baking tray and put the tray in the oven for 5 min or until the oil is hot

Peel and finely chop the shallot. Combine the chopped shallot with the mayo and the juice of 1/2 lemon in a small bowl

Season with a pinch of salt and give everything a good stir – this is your lemon mayo. Once done, drain the softened chunky chips and reserve the pot, give them a shake in the colander until the edges have fluffed up a little

Carefully remove the baking tray of hot oil from the oven and add the fluffed chunky chips. Season them with salt and turn them a few times until they're fully coated in the oil

Put the tray in the oven for 30 minutes or until golden and crisp

Meanwhile, combine the Marmite and 80ml very cold water in a small bowl, stirring continuously until fully combined – this is your Marmite water

Add 60g flour to a separate large bowl with half of the red wine vinegar (save the rest for later!), a generous pinch of salt and the Marmite water

Stir everything together thoroughly until there are no lumps, then set aside for later – this is your batter

Pat the cod fillets dry with kitchen paper. Season the cod with a pinch of salt and sprinkle both sides with flour until fully coated, then tap off any excess

Reboil a kettle

Heat a large, wide-based pan (preferably non-stick) with a very generous drizzle of vegetable oil (enough to coat the base of the pan) over a high heat

Once the pan is hot, dip the floured cod into the batter and turn it several times until fully coated, then add the coated cod to the pan and cook for 3-4 min on each side until cooked through, golden and crispy – this is your battered fish

Tip: Your fish is cooked once it turns opaque and flakes easily

Add the blanched peas to the reserved pot, cover them with boiled water and bring to the boil over a high heat

Cook for 1 min or until they're warmed through, then drain and return to the pot with a knob of butter

Mash the peas until they come together nicely – these are your mushy peas

Cut the remaining lemon into wedges