Cut steak crosswise into thin slices, then cut each slice into thin strips*. Place meat in medium bowl. Add garlic and crushed pepper; mix lightly. Combine dressing, hoisin sauce, soy sauce and cornstarch.
Heat oil in large skillet on medium-high heat. Add meat, in batches; stir-fry 1-2 minutes or until meat is barely pink in the center. Transfer to plate, set aside.
Add carrots and celery to skillet; stir-fry 2 minutes. Return meat to skillet along with the dressing mixture; stir-fry 1-2 minutes or until meat is done and sauce is slightly thickened. Stir in onions.