HEAT oven to 400°F.
HEAT oil in large skillet on medium-high heat. Add peppers and onions; cook and stir 5 min. Add meat; mix well. Cook 10 min. or until browned, stirring occasionally; drain. Stir in barbecue sauce; simmer on medium-low heat 10 min., stirring occasionally.
SPOON into 9-inch pie plate; sprinkle with cheese. Prepare muffin batter as directed on package; spoon over cheese, completely covering cheese layer.
BAKE 20 min. or until golden brown. Let stand 5 min. before serving.