In a medium skillet put 1 tablespoon butter, the diced stems, onion, bell pepper and parsley. Add garlic also at this time if using. Saute until soft. Add spices, lemon juice and bread crumbs. Mix well and stuff the 12 mushrooms.
2Dot each with a little of the remaining 1 tablespoon butter. Bake in a buttered pyrex baking dish at 375 for 20 minutes. Makes 12 stuffed mushrooms.