Heat oven to 350°F. Spray 13x9-inch (3-quart) baking dish with cooking spray.
In 12-inch skillet, cook beef, mushrooms, salt and pepper over medium-high heat 7 to 9 minutes, stirring frequently, until beef is thoroughly cooked; drain. Place in baking dish. Arrange cheese over beef mixture, overlapping slices if needed.
In same skillet, melt butter over medium-high heat. Add onions and bell peppers. Cook over medium-high heat 3 to 5 minutes, stirring frequently, until peppers are crisp-tender. Stir in garlic; cook 1 to 2 minutes longer. Spoon over cheese in baking dish.
Separate dough into 8 biscuits. On lightly floured surface, pat biscuits into 5-inch circles. Arrange biscuits over vegetable mixture.
Bake 35 to 40 minutes or until biscuits are golden brown on top.