1In medium nonmetal bowl or resealable food-storage plastic bag, mix oil, vinegar, thyme, red pepper and garlic. Add beef; stir to coat with marinade. Cover dish or seal bag and refrigerate, stirring beef occasionally, at least 4 hours but no longer than 24 hours to marinate.
2Heat gas or charcoals grill. Remove beef from marinade; reserve marinade. On each of six 10- to 12-inch metal skewers, thread beef, corn and bell peppers alternately, leaving space between each piece. Brush with marinade.
3Place kabobs on grill rack over medium heat. Cover grill; cook 15 to 20 minutes for medium beef doneness, brushing with marinade and turning frequently. Discard any remaining marinade.