Clean and wash the peppers and zucchini and cut them into pieces or slices. Clean the mushrooms, wash briefly and cut in half. Peel and finely chop the onion.
Heat the oil in a coated pan. Sauté the mushrooms in it vigorously.
Take it out. Fry onion, bell pepper and zucchini in hot frying fat. Add the mushrooms again. Add tomatoes and juice, chop tomatoes a little bit. Season with oregano, salt and pepper. Bring everything to the boil and simmer for about 5 minutes.
Wash the basil, cut into strips and add to the vegetables. Season to taste and place in a greased casserole dish. Grate the cheese coarsely and sprinkle over it. In a preheated oven.
(electric cooker: 200 °C/circulating air: 175 °C/gas: see manufacturer) bake for about 15 minutes.