Peel the vegetable onion and cut into slices. Clean, wash and cut the peppers into large cubes. Clean, wash and dice the zucchini. Clean, wash and cut the tomatoes into eighths. Heat oil in a large pan.
Fry the onions until golden brown. Add the diced peppers and zucchini and cook for about 2 minutes. Add tomato pieces. Season the vegetables with salt, pepper and herbs and put them into an ovenproof dish.
Wash the fish fillets, dab dry, sprinkle with lemon juice, salt lightly and arrange in flakes in the vegetable bed. Cook in the preheated oven (electric cooker: 200 °C/ gas: level 3) for 20-25 minutes.
Garnish lemon slices and parsley bouquets. Season the crème fraîche with a little coarsely ground pepper and add it in a small bowl. Boiled potatoes taste good with it.