Heat oven to 400°F. Heat large ovenproof nonstick skillet on medium-high heat. Remove steak from marinade; discard marinade. Place steak in skillet; sprinkle with garlic powder. Place onions around steak; cook 3 min. or until bottom of steak is browned. Remove steak from skillet. Toss carrots and peppers with remaining dressing. Add to skillet; stir to mix with onions. Return steak, browned side up, to skillet.