1 lb. ground beef
1/3 c. chopped onion
10 1/2 oz. can pizza sauce with cheese
2 1/2 oz. jar Green Giant sliced mushrooms, drained
1 tsp. oregano leaves
4 oz. (1 c.) shredded mozzarella cheese
8 hamburger buns, sliced

In large skillet, brown ground beef and onion; drain. Stir in pizza sauce, mushrooms and oregano. Refrigerate at least 2 hours or until served. Before serving, heat oven to 400 degrees. Stir cheese into hamburger mixture. Spoon onto sliced hamburger buns; place on cookie sheet. Bake 10 minutes, or until cheese is melted. Makes 16 sandwiches.