Heat coals or gas grill for direct heat.
Cut beef into 24 one-inch pieces. Thread beef, bell pepper and mushrooms alternately on each of eight 10- to 12-inch metal skewers, leaving space between each piece. Mix remaining ingredients.
Cover and grill kabobs 4 to 6 inches from medium heat 15 to 18 minutes, turning and brushing kabobs 3 or 4 times with oil mixture, until beef is desired doneness and vegetables are tender.