HEAT oven to 350°F.
PLACE chicken in 13x9-inch baking dish sprayed with cooking spray; sprinkle with garlic powder. Cover with stir-fry vegetables. Combine corn and dressing; spoon over vegetable layer in dish.
ADD hot water to stuffing mix; stir just until moistened. Spoon over corn mixture; cover.
BAKE 45 min. or until chicken is done (165°F), uncovering for the last 15 min.