In a large shallow dish, combine the taco seasoning, tomato juice and oil; mix well. Remove 1/2 cup for basting; refrigerate. Add beef and turn to coat. Cover; refrigerate for at least 5 hours., Drain and discard marinade from beef. On metal or soaked wooden skewers, alternately thread beef, peppers, onion and tomatoes. Grill, uncovered, over medium heat for 3 minutes on each side. Baste with reserved marinade. Continue turning and basting until meat reaches desired doneness, 8-10 minutes. If desired, serve with salsa con queso or sour cream.