Salt cod in Biscay pepper sauce (Bacalao a la vizcaína)

1. Soak the salt cod in cold water for 36-48 hours (changing the water several times a day), then pat dry and remove the bones.

2. Seed the choricero peppers and soak them in hot water for 1 hour; if you can't find them, use 3 pointed red peppers and 2 teaspoons of smoked paprika instead.

3. In a pan, cook the thinly sliced onion and garlic in 3 tablespoons of olive oil very slowly for 30-40 minutes until soft and sweet – don't let them brown.

4. Add the flesh scraped from the choricero peppers and the chopped tomato, cook for 10 minutes, then blend smooth with a little soaking water and push through a sieve to get a velvety brick-red sauce.

5. Dust the cod pieces with flour and fry them in the remaining olive oil for 2 minutes per side; put them in an ovenproof dish, pour over the sauce and cook together in the oven at 180 °C (or over low heat) for 10-12 minutes.

6. Serve with white rice or boiled potatoes and bread.

Tip: The sauce keeps well in the fridge – make a double batch, it's excellent with meat and eggs too.