PREPARATION:

1. Place lamb in large self-sealing plastic food storage bag. Combine remaining ingredients in small bowl. Pour over meat; seal bag. Refrigerate 4 to 6 hours or overnight, turning bag occasionally to distribute marinade.
2. Preheat charcoal grill and grease grill rack. Remove meat from refrigerator and bring to room temperature. Remove meat from marinade and drain briefly; reserve marinade. Place meat on grill 4 to 6 inches above solid bed of coals (coals should be evenly covered with gray ashes). Cook, uncovered, about 50 minutes for medium or until internal temperature reaches145°F when tested with meat thermometer inserted into the thickest part of roast. Baste frequently and turn as needed to brown evenly.
3. Transfer roast to cutting board; cover with foil. Let stand 10 to 15 minutes before carving. Internal temperature will continue to rise 5°F to 10°F during stand time.