In medium shallow dish, combine marinade ingredients, adding pepper, as desired; whisk until blended. Remove and reserve 3/4 cup for basting.

With sharp knife, slice sirloin into 1/4-inch strips. Place steak in remaining marinade in dish, turning to coat. Cover and marinate in refrigerator 30 minutes, turning once.

Remove steak from marinade; discard marinade. Thread steak on skewers. Place steak on grid over medium ash-covered coals. rill, uncovered, 8-10 minutes, turning once for medium-rare to medium doneness. Baste occasionally with reserved marinade.

Place remaining basting marinade in small saucepan; bring to a boil for 1 minute. Spoon hot marinade over beef and sprinkle with toasted sesame seeds, as desired.

Recipe and Photo Courtesy of The Washington State Beef Commission.