Melt your butter in a saute pan until it becomes quite hot but not burning, Quickly saute your chicken and mushrooms until the chicken is lightly brown. Add your proscuitto and herbs. Add your marsala and cook rapidly to reduce it by half. This is a very quick dish and you will know when it is done by its taste. The flavors should all be blended in a wonderful sauce. Now remove it to a broiling pan... Top with cheese and broil only until the cheese has melted. Sprinkle with chopped parsley...