Preheat oven to 350 degrees F.
Cook beef until no longer pink; drain.
Quarter biscuits; place in a greased shallow 3-quart baking dish.
Top biscuits with pizza sauce.
Sprinkle beef over sauce.Layer with green pepper, onion, mushrooms, pepperoni, and cheeses.
Bake, uncovered, for 25–30 minutes or until cheese is melted.Let stand 5–10 minutes before serving.