Cod

Pat the fillets dry, season them and fry in a lightly oiled pan over a medium heat for about 3–4 minutes on each side, depending on thickness. Turn once, using a wide fish slice; the flesh is ready when opaque and easy to flake.

Bake cod at 200°C for about 10–15 minutes, depending on the thickness of the fillet. It is cooked when the centre is opaque and flakes easily, or reaches 63°C on a food thermometer.

Yes. Put frozen portions in a single layer in a baking dish, brush with oil and bake at 200°C for roughly 20–25 minutes; check that the centre is opaque and flakes easily. For pan-frying, thaw it overnight in the fridge first and pat it dry so it browns rather than steams.

Keep cod covered in the fridge at 0–5°C and cook it within a day or two of buying it. To freeze it, wrap the portions tightly and thaw them in the fridge before cooking.

Cod works well with lemon, parsley, butter, garlic and capers, and is often used in fish pie, fish cakes and battered fish. Serve it with potatoes and peas, or add it to a tomato-based stew.

Haddock is a close substitute in fish pie, fish cakes and batter: it has 92 kcal and 21.5 g protein per 100 g, compared with 106 kcal and 24 g protein in cod. Alaska pollock also works well in recipes calling for mild, flaky white fish.

Raw cod can carry parasites, so it is safest to cook it thoroughly unless it has been handled and prepared specifically for raw eating. For cooked cod, aim for an opaque centre that flakes easily, or 63°C at the thickest point.