Mix Gravy Mix, oil, vinegar, water and garlic in small bowl until well blended. Reserve 2 tablespoons for brushing. Place steak in large resealable plastic bag or glass dish. Add remaining marinade; turn to coat well.
Refrigerate 30 minutes or longer for extra flavor. Remove steak from marinade. Discard any remaining marinade. Alternately thread steak and vegetables onto skewers.
Broil or grill over medium-high heat 8 to 10 minutes or until steak is desired doneness and vegetable are tender, turning occasionally. Brush with reserved marinade halfway through cooking.