When soft, add 4 peeled tomatoes, cut into slices. In a fireproof baking dish, arrange a row of eggplant, onions pour over them tomatoes and arrange some zucchini on top.
Every line is sprinkled with grated cheese. Cover with a thin row of tomato slices and sprinkle with breadcrumbs. Bake in a moderate oven for about 30 minutes.