1. Combine vinegar, oil and garlic in large bowl. Brush steaks with 1 tablespoon of the balsamic mixture, sprinkle with pepper and salt. Cover and refrigerate.

2. Add bell peppers, onion, and mushrooms to remaining balsamic mixture, toss to coat. Let stand at room temperature 30 minutes or cover and refrigerate 2 hours stirring occasionally.

3. Heat grill. Drain vegetables, reserving marinade. Alternately thread vegetables onto 4 (10"-12") metal or bamboo skewers.**

4. Grill steaks and vegetables, covered over medium heat or coals 8 to 12 minutes for medium-rare steak and crisp-tender vegetables, turning and brushing occasionally with reserved marinade.

5. Remove steaks and vegetables from grill. Cover loosely with foil, let stand 5 minutes. Serve steaks with vegetables.

** If using bamboo skewer, soak them in cold water for at least 20 minutes before using.