Select and clean a large sar or red bream weighing about 1 kg (2¼ lb) or several smaller ones. Make deep incisions in the back of the fish. Insert feathery sprigs of fresh fennel in the incisions, and put some sprigs of fresh thyme in the fish’s belly together with a knob of butter and salt and pepper.
Place the fish on its grid (see above), pour over it 225 ml (8 fl oz) of dry white wine and 1 tablespoonful of olive oil, which will then collect below. Add a few slices of tomato to the liquid, and place thin slices of lemon on top of the fish. Cook in a moderate oven (355°F, 180°C, gas 4) for 15 to 25 minutes (less for the sar than for the dorade), basting from time to time although this is not essential. Serve with the cooking juices strained off and used as a sauce.