How to make
Cut the mushrooms and onions cut small pieces, add salt and sauté them in the heated oil. Add the chopped tomatoes and parsley. Mix and after about 5 minutes, transfer the mixture into a tray.
For the sauce, heat olive oil in a pan, add the flour, stir and slowly add the milk. Pour the resulting sauce over the dish and bake in a preheated moderate oven until browned.
While still hot, sprinkle it with grated cheese and serve. Enjoy your meal!