Name: Fish and chips with no-waste shell curry sauce
Prep time: 50 min
Cook time: 1 h 55 min
Total time: 2 h 45 min
Yield: Serves 2
Ingredients: 2 large floury potatoes, scrubbed (no need to peel); 2 tbsp olive oil; 2 x 200g sustainable firm white fish fillets; 1 tbsp plain flour; ¼ tsp paprika; 250g frozen peas; 15g salted butter; 2 tarragon sprigs, leaves chopped; Lemon wedges to serve; About 400g crustacean shells (prawn or langoustine heads and tails, crab and lobster shells, raw or cooked); 2 tbsp olive oil; 2 banana shallots, thinly sliced; 1 large carrot, thinly sliced; 1 small fennel bulb, thinly sliced; 2 garlic cloves, sliced; ½ tbsp curry powder; 200ml dry white wine; 1 bay leaf; ½ tsp black peppercorns; 50ml double cream; 80g salted butter, cubed

Fish and chips with no-waste shell curry sauce

Upgrade your Friday night fish and chips with a very special curry sauce. Using leftover crustacean shells to make a stock, then enriching it with cream and butter gives an intense sauce any fancy French restaurant would be proud of – never mind your local chippy. For more delicious no-waste ideas, try our fish scrap croquettes and crispy fish skin crackling.

Freezable

Serves2

Hands-on50 min. Oven time 30-35 min

Oven1 hour 55 min

DifficultyMedium

Method

To make the sauce, put the shells in a large heavy bowl and use the end of a rolling pin to bash into smaller pieces. Heat 1 tbsp of the oil in a large saucepan over a medium-high heat, then add the shells, shallots, carrot, fennel, garlic and a large pinch of salt. Cook for 15-20 minutes, stirring regularly, until golden and starting to caramelise.
Stir in the curry powder and cook for 1 minute. Add the wine and bubble until it’s almost all reduced, then add 1 litre water, the bay leaf and peppercorns. Bring to the boil, then reduce to a simmer and bubble gently for 1 hour, stirring occasionally.
When the sauce has had an hour, pass it through a sieve into a medium saucepan, then return to the heat and boil to reduce by two-thirds (about 20 minutes).
Meanwhile, prepare the chips. Heat the oven to 190°C fan/gas 6½ with a tray inside to heat up. Cut the potatoes into 1cm thick chips and rinse in cold water. Tip into a saucepan, cover with salted water, bring to the boil, then simmer for 5 minutes. Drain and leave to steam dry. Add half the oil to the tray in the oven once it’s hot, then put the tray back in the oven for 3 minutes. Season the chips with salt, then tip carefully into the hot oil and turn to coat. Roast for 30-35 minutes, turning halfway, until crisp and golden. Season with salt flakes as soon as the chips come out of the oven.
Put the fish on a plate and dry a little with kitchen paper. Season with salt and leave for a few minutes. Dust with the flour and paprika, then season with pepper.
Once the sauce has reduced, turn the heat to low and stir in the cream. Add the butter, a few cubes at a time, stirring all the time, until melted and emulsified into a glossy sauce. Season to taste, then keep warm over a low heat.
Bring a small pan of salted water to the boil and cook the peas for 3 minutes. Drain and return to the pan. Add the butter and half the tarragon, then mash with a potato masher. Season and cover to keep warm.
Heat a nonstick frying pan over a medium heat and add the remaining 1 tbsp oil. Once hot, add the fish fillets. Cook for 2-4 minutes (depending on thickness) until the edges are starting to turn opaque. Flip and cook for another 2-4 minutes until the flesh is opaque all the way through.
Serve the fish, chips and mushy peas with the curry sauce for pouring over. Add a wedge of lemon for squeezing.