Beef And Ham Roll-Ups
["8 oz. canned or fresh mushrooms, sliced", "3/4 lb. deli imported ham *", "1/2 c. chopped onion", "3/4 lb. deli roast beef *", "1/4 c. margarine"]
["*I usually buy the meat by the number of slices I need rather than by the pound."]
["fresh mushrooms", "deli", "onion", "deli roast beef", "margarine"]