Preheat the oven to 190°C (375°F) Gas Mark 5. First scale the fish by running the blunt edge of a large knife over the skin of the fish going from the tail to the head.

Using a filleting knife, cut along the belly of the fish from just under the head to the vent, the small opening near the tail. Clean out the cavity of the fish, leaving in the liver if desired. Rinse the fish well inside and out and pat dry.

Trim the fins and neaten the tail with kitchen scissors. Place the fish head to tail in an ovenproof dish. Mix the oil and the wine together and squeeze the juice from one of the lemons. Add the garlic, salt and pepper and pour over the fish. Place on the tomato slices or if using canned tomatoes, crush them slightly and spoon over. Bake for about 25 minutes, basting frequently until the fish is tender. Garnish with dill.