Preparation Combine first 8 ingredients in blender. Puree until rosemary is completely ground, about 3 minutes. Place lamb in large glass baking dish with 2-inch high sides. Pour marinade over lamb, making certain all parts of lamb are covered with marinade. Cover; chill at least 8 hours or overnight. Let stand 2 hours at room temperature before cooking. Prepare barbecue (medium-high heat). Remove lamb from marinade. Sprinkle both sides of lamb generously with salt and pepper. Grill lamb until brown and crusty on outside and thermometer inserted into thickest part registers 130°F for medium-rare, turning occasionally, about 20 minutes. Transfer to platter and tent with foil. Let stand 10 minutes. Cut on diagonal into thin slices.
Preparation Combine first 8 ingredients in blender. Puree until rosemary is completely ground, about 3 minutes. Place lamb in large glass baking dish with 2-inch high sides. Pour marinade over lamb, making certain all parts of lamb are covered with marinade. Cover; chill at least 8 hours or overnight. Let stand 2 hours at room temperature before cooking. Prepare barbecue (medium-high heat). Remove lamb from marinade. Sprinkle both sides of lamb generously with salt and pepper. Grill lamb until brown and crusty on outside and thermometer inserted into thickest part registers 130°F for medium-rare, turning occasionally, about 20 minutes. Transfer to platter and tent with foil. Let stand 10 minutes. Cut on diagonal into thin slices.