About two hours before cooking, trim the fat and skin from outside of lamb if necessary. Dry the
meat with paper towels. Combine the rosemary, salt, and pepper in a small bowl. Sprinkle the
mixture over both sides of lamb and press the seasonings into the meat. Wrap snugly in plastic
and refrigerate. Remove from refrigerator 30 minutes before cooking.
Prepare a hot charcoal fire or preheat a gas or electric grill.
Place the lamb on the grill and cook, covered, for about 7 minutes. Turn the lamb and cook,
covered, until an instant-read thermometer inserted on an angle into thickest part of meat registers
120°F, for medium-rare doneness, about 7 minutes more. Place lamb on a platter or carving board
and allow to rest for 5 minutes, covered with foil, before carving. Cut into very thin slices across the
grain and serve immediately.
