Baked cod fillets in tomato, green olive and caper sauce. Includes thickness-based timing, safe doneness checks and simple serving suggestions.
A short simmer gives the tomato sauce time to lose its raw edge before the cod is added. The fish then bakes gently on top, where you can check it easily. Olives and capers bring salt of their own, so season the sauce cautiously and taste it before placing the raw fish in the dish.
Serves: 4 | Estimated preparation: 15 minutes | Estimated cooking: 35 minutes | Estimated total: 50 minutes.
Recipe development note: this recipe has not been kitchen-tested by Tasty Food. Times are estimates; follow the texture and safe-temperature checks in the method. The featured image is an AI-generated serving illustration and may differ from your result.
Equipment
A saucepan or ovenproof sauté pan, a baking dish if needed, a fish slice and a food thermometer.
Ingredients
- 4 skinless cod fillets, about 150–180 g each, thawed if frozen
- 2 tablespoons olive oil, divided
- 1 small onion, finely chopped
- 3 garlic cloves, finely chopped
- 1 × 400 g can chopped tomatoes
- 150 ml tomato passata
- 60 ml water
- 70 g pitted green olives, sliced
- 1 tablespoon capers, rinsed and drained
- 1/2 teaspoon dried oregano
- 1/4 teaspoon fine salt, plus more only if needed
- 1/4 teaspoon black pepper
- 1 lemon, half juiced and half cut into wedges
- 2 tablespoons chopped parsley
- Boiled potatoes or crusty bread, to serve
Instructions
- Prepare the fish and oven. Heat the oven to 200°C/180°C fan/400°F. Pat the cod dry and check carefully for pin bones, removing any with clean fish tweezers. Keep the fish refrigerated while making the sauce. Choose a baking dish that holds the fillets in a single layer with a little space between them.
- Soften the aromatics. Warm 1 tablespoon oil in a saucepan over medium heat. Add onion and cook for 6–7 minutes until soft. Stir in garlic and oregano for 30 seconds, keeping the garlic pale. If using an ovenproof sauté pan large enough for all the fish, you can finish the dish in that pan.
- Reduce the tomato sauce. Add chopped tomatoes, passata and water. Simmer uncovered for 10–12 minutes, stirring occasionally, until slightly thickened. Stir in olives and capers. Taste at this point and add only as much of the measured salt as needed. Spread the sauce in the baking dish if using a separate one.
- Bake according to thickness. Set cod over the hot sauce. Drizzle with the remaining oil and season with pepper and any remaining salt that is needed. Bake for about 10–15 minutes, checking earlier for thin fillets. The thickest part must reach 63°C/145°F, and the flesh should become opaque and separate readily. Thick pieces may take longer.
- Finish and serve. Remove the dish as soon as the fish is ready. Squeeze over 1–2 teaspoons lemon juice, then taste a spoonful of sauce and add more only if wanted. Scatter with parsley. Lift each fillet carefully with a fish slice and serve with sauce, lemon wedges and potatoes or bread.
Cooking notes and substitutions
Working with frozen fish
Thaw covered in the refrigerator, drain away thawing liquid and pat the fillets dry. A partly frozen centre cooks less evenly, while excess surface water can dilute the sauce. Keep raw fish and its utensils away from garnishes and serving plates.
Sauce and fish substitutions
Pitted black olives can replace green olives. If capers are unavailable, omit them and taste for acidity at the end. Other firm white fish fillets can work, but thickness affects timing more than the label on the packet; keep the temperature check.
Storage and reheating
Fish is best freshly cooked. Refrigerate leftovers promptly within 2 hours, or 1 hour above 32°C/90°F, and use within 3 days. Reheat covered in the sauce until the centre reaches 74°C/165°F. The texture will be firmer after reheating, so avoid cooking a large extra batch solely for leftovers.
Allergens and food safety
Contains fish. Serving with bread adds wheat. Check olives and capers for their specific labelling. Keep refrigerated food at 4°C/40°F or below. Use clean utensils when checking cooked food.
Food safety reference: CDC food safety guidance. For chilling and reheating guidance, see USDA leftovers guidance.
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