1/2 C Red cooking wine
Blend cooking wine, oil, garlic powder, Worcestershire sauce, and vinegar in a container. Put the beef in a shallow pan and cover with mixture. Marinate for at least 4 hours or overnight in the refrigerator. Place the beef pieces alternately with the vegetables on wooden or metal skewers and grill or broil until done. Baste the kabobs with the remaining marinade while cooking. Add tomatoes at end of cooking.