Prime rib roast come with and without the bone. For a boneless roast, place meat in a heavy roasting pan and place in a 450 degree oven to sear the meat. Cook 15 to 30 minutes, turning to sear all sides. Turn oven down to 325 and continue to cook for 13 to 15 minutes per pound. Cook to rare, 140 degrees. Let meat stand for 15 to 20 minutes before cutting.