Hobo Sandwich

Heat oven to 400F.

Melt the butter or margarine in a frying pan. Add the mushrooms and sliced onion and saute until lightly browned and heated through.

Place the pita breads on cookie sheets. Top each bread with 3 ounces of roast beef. Evenly divide the sauteed onion-and-mushroom mixture into 4 portions and place it on top of the roast beef. Top off with 1/4 cup of shredded Cheddar cheese on each bread.

Bake in oven for 5 minutes or until lightly browned. Serve warm.