Wash the fish, pat dry, salt and pepper. Place in a baking dish. Thinly slice the garlic clove, peel and halve the onion and cut into strips. Halve the peppers, remove the seeds and cut the peppers into thin strips.
Place the tomatoes in boiling water, take them out of the pot after 30 seconds and rinse. Then peel, quarter, remove the core and cut the tomatoes into small cubes.
Now mix the garlic, onions, peppers to taste, tomatoes, lemon peel and a little juice, rosemary and oregano with the olive oil and spread on the fish fillet. Sprinkle pepper over the top with a pepper mill and add a little salt if necessary. Now cover the baking dish with aluminum foil and cook the fish in the oven at 180 degrees for about 15-20 minutes. Then arrange on a plate. It goes well with boiled potatoes or just baguette.