Preparation :
After gutting and cleaning the fish, place it in a baking dish. Peel and slice the onion and carrot thinly, put into a saucepan with olive oil, and margarine, saute for a while. If tomatoes are used, skin and slice the tomatoes, scoop out the seeds and add to the oil. Cook until the tomatoes reach the consistency of tomato sauce. Add chopped mushrooms and cook. Later season with white wine, wwater, red pepper and salt, and boil without covering until the sauce thickens. Pour the sauce over the fish in the baking dish. Bake in medium hot oven which is heated from the bottom. Bake for 15 minutes.Place on a plate and serve.