POUR 3/4 cup of the dressing over steak in shallow glass or plastic dish; cover. Refrigerate at least 30 minutes to marinate. Drain; discard marinade.
PREHEAT greased grill to medium heat. Grill steak 8 minutes on each side or until cooked through. Cut steak across grain into thin strips.
PLACE greens in large salad bowl. Add steak, tomatoes and remaining 1/4 cup dressing; toss to coat. Sprinkle with croutons.