Kalpachetata and stumps of mushrooms steamed in boiling salted water and removable. In the oil fry the onion, sprinkle breadcrumbs is, add the egg, chopped parsley and bacon, salt and mustard. Mushrooms filled with this mixture and arrange in a baking dish with butter. Sprinkle with grated feta cheese, cover with slices of tomatoes and bake the dish to stand in a moderate oven.