HEAT oven to 450°F.
TOSS potatoes with dressing and pepper in 15x10x1-inch pan sprayed with cooking spray. Spread into single layer.
BAKE 40 min. or until vegetables are tender, stirring in onions after 20 min.
SPRINKLE with parsley and bacon; stir. Top with cheese. Bake 2 min. or until cheese is melted.