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, lightly score both sides of beef steak in a crisscross pattern.
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. Place steak on grid over medium, ash-covered coals.
Grill, uncovered, 17 to 21 minutes for medium rare to medium doneness, basting occasionally with reserved 3/4 cup marinade and turning once. Place remaining basting marinade in s mall saucepan; place on grid of grill and bring to a boil.
Meanwhile carve steak diagonally across the grain into thin slices; arrange on platter.
Spoon hot marinade over beef, as desired.
Garnish with orange slices and rosemary sprigs.
Tip: To broil, place steak on rack in broiler pan so surface of meat is 2 to 3 inches from heat. Broil 13 to 18 minutes, basting occasionally with reserved 3/4 marinade and turning once.