Bread crumbs Cheese, Parmigiano, grated Clean the mushrooms thoroughly and remove and chop up their stems. Saute onions and garlic in quarter cup of olive oil until transparent. Add chopped mushrooms stems, chopped prosciutto, parsley, marjoram, salt and pepper. Saute for about 2 minutes, then add wine. Add bread crumbs until mixture is consistency of mush. Coat mushroom tops with remaining olive oil. Stuff each mushroom with a tablespoon of the mixture, then sprinkle with Parmigiano cheese and bake at 190ºC for 3 7 minutes, depending on the size of the mushrooms.