HEAT oven to 450ºF.
PLACE fish on baking sheet sprayed with cooking spray. Brush with 2 Tbsp. dressing. Bake 12 to 15 min. or until fish flakes easily with fork.
MEANWHILE, heat oil in large nonstick skillet on medium heat. Add next 3 ingredients; cook and stir 4 min. or until crisp-tender. Remove from heat; stir in remaining dressing.
SPOON cooked vegetables onto serving plate; top with fish and onions.
serving size = 1/4 recipe (194 g)