1 lb. ground beef
1 large onion, chopped
1 medium green pepper, chopped
8 oz. sliced mushrooms
1 jar pizza sauce
1/2 tsp. garlic salt
8 oz. macaroni, cooked and drained
1 1/2 c. Sargento Pizza Double cheese, divided
1 (3 1/2 oz.) pkg. pepperoni

Combine first 4 ingredients in skillet. Cook over medium heat, stirring until meat crumbles and browns; drain well. Stir in pizza sauce, garlic salt, macaroni and 1 cup cheese. Spoon mixture into lightly greased 11 x 17 x 1 1/2-inch baking dish. Arrange pepperoni on top. Cover and bake at 350°F for 25 to 30 minutes. Sprinkle with remaining cheese and bake 5 additional minutes.