Sirloin Kabobs are one of the "fun" barbecue meals.  Place beef in bowl.  Mix your favorite marinade; pour over beef, cover and refrigerate, stirring occasionally, at least one hour.  Thread beef cubes and vegetables on skewers; brush with marinade.  Either broil in a grill or an oven.  In an oven broil kabobs with tops about eight inches from heat; turn and brush with marinade.  Broil until done no more than medium rare.  Brush with marinade again before serving.  On a grill use the same approach as with a Sirloin Steak brushing now and then with your marinade.