Baked Cod in Rich Tomato Sauce

Flaky cod fillets nestled into a rich, garlicky tomato sauce with olives and herbs, all baked together in one dish. It is light yet deeply savoury, comes together in half an hour, and needs nothing more than crusty bread to finish.

This is the fish supper to reach for on a busy weeknight: skinless cod fillets baked in a punchy tomato sauce that practically makes itself. You soften garlic and onion, simmer a quick sauce, then let the oven do the rest. The result is flaky, moist fish in a sauce you will want to mop up with bread.

Ingredients

• 4 fillets skinless cod fillets — about 150g each, thawed if frozen
• 2 tbsp olive oil
• 1 onion — finely chopped
• 3 cloves garlic — thinly sliced
• 400 g tinned chopped tomatoes — 1 tin
• 1 tbsp tomato purée
• 1 tsp dried oregano
• 0.5 tsp caster sugar — to balance the tomatoes
• 60 g pitted black olives — roughly chopped
• 1 pinch chilli flakes — optional
• 1 handful fresh flat-leaf parsley — chopped, to finish
• 1 lemon — half juiced, half in wedges to serve
• to taste sea salt and black pepper

Method

1. Preheat the oven to 200C/180C fan/gas 6. Pat the cod fillets dry with kitchen paper and season lightly all over with salt and pepper.
2. Heat the olive oil in an ovenproof frying pan or shallow casserole over a medium heat. Add the onion and cook for 5 minutes until softened, then stir in the garlic and chilli flakes and cook for another minute until fragrant.
3. Add the tomatoes, tomato purée, oregano and sugar. Simmer for 5 minutes, stirring now and then, until the sauce thickens slightly. Stir through the olives and lemon juice, then taste and adjust the salt and pepper.
4. Nestle the cod fillets into the sauce, spooning a little over the top of each so they stay moist. Leave the tops just peeking out.
5. Transfer the pan to the oven and bake for 15 to 18 minutes, until the cod is opaque and flakes easily with a fork, with no translucent or raw-looking flesh remaining and the sauce is piping hot throughout.
6. Scatter with the chopped parsley and serve straight from the pan, with lemon wedges on the side for squeezing over.

Serve it with

• Warm crusty bread or focaccia to soak up the sauce
• Buttery new potatoes
• A crisp green salad with a lemon dressing
• Steamed green beans or tenderstem broccoli
• Fluffy couscous or orzo

Why this works

Baking the cod partly submerged in the sauce keeps it gently steamed and moist, while the quick pan-simmered tomato base concentrates flavour without turning watery.

Common swaps

• Swap cod for haddock, pollock or another firm white fish.
• Use a tin of cherry tomatoes for a slightly sweeter, chunkier sauce.
• Capers work brilliantly in place of, or alongside, the olives.
• Stir a handful of baby spinach into the sauce before adding the fish for extra greens.
• No fresh parsley? A little chopped basil or dried is fine.

Common mistakes to avoid

• Not drying the fish first, which waters down the sauce and stops it seasoning well.
• Overbaking the cod until it turns dry and rubbery, check it at 15 minutes.
• Under-seasoning the tomato sauce, taste and adjust before the fish goes in.
• Fully burying the fillets, leaving the tops exposed helps them cook evenly.

Storage, freezing & reheating

Storage: Cool leftovers quickly and keep covered in the fridge for up to 2 days.

Reheating: Reheat gently in a covered pan or in the oven at 180C until piping hot throughout; avoid the microwave on high, which can toughen the fish.

Allergen notes: contains Fish. Always check individual product labels.

Estimated nutrition

Per serving, estimated from typical ingredient values — not a substitute for precise dietary calculation.