REMOVE and discard stems from mushrooms. Brush mushroom caps with dressing; place on rack of broiler pan. Broil, 4 inches from heat, 5 min.
PRESS sausage into mushroom caps, adding about 1 tsp. sausage to each cap. Sprinkle with cheese.
BROIL, 4 inches from heat, 3 to 5 min. or until cheese is melted. Serve hot.