1 can (4 ounces) mushroom stems and pieces, drained
1 can (15 ounces) pizza sauce
1 cup chopped green pepper
1/2 cup chopped onion
1 cup shredded cheddar cheese
1 cup shredded part-skim mozzarella cheese
Preheat oven to 350°. In a large skillet, cook beef over medium heat 6-8 minutes or until no longer pink, breaking into crumbles. Meanwhile, cut biscuits into quarters; place in a greased 13x9-in. baking dish. Drain beef; sprinkle over biscuits.
Layer with pepperoni, mushrooms, pizza sauce, green pepper and onion. Bake, uncovered, 15 minutes. Sprinkle with cheeses. Bake 15-20 minutes longer or until cheese is melted. Let stand 5-10 minutes before serving.