Salt and pepper to taste Combine lemon juice,onion,vinegar,oil,cumin,garlic powder and red pepper in bowl.Add beef cubes,stirring to coat.Thread beef cubes and pepper pieces onto 4 skewers,adding 1 onion to each.Place kabobs on rack in broiler so surface of meat is 3 to 10 cm from heat.Broil dozen to 15 minutes,turning occasionally,to desired doneness.Season with salt and pepper to taste.Makes 4 servings.