Rib roast, also called prime rib, is from the rib section of the forequarter and is a favorite for celebrations and holidays. The ribs encase wonderfully tender, juicy, and flavorful meat that is perfectly marbled and covered with a substantial layer of fat. Large rib roasts include the short ribs and can serve up to 16 people. Smaller ones, such as we suggest for grilling, are trimmed, with the short ribs removed, and are great for four to six people. For the grill, buy a three- or four-rib roast. All the roast needs is a little sliced garlic and salt and pepper. It has enough fat and so requires no olive oil. You will love how a rib roast tastes when grilled, served with a horseradish cream sauce.
Prepare a charcoal or gas grill, arranging the coals for indirect cooking. Lightly spray the grill rack with vegetable cooking spray. The coals should be moderately hot to hot.
Using a sharp knife, make small slits down the meaty side of the roast. Insert the garlic in the slits. Sprinkle with salt and pepper.
Sear the meat over intense heat on the bone side and the narrow sides for 1 or 2 minutes per side. Sear the meaty side for about 3 minutes. Turn the roast with tongs, if possible, to avoid piercing the meat so that none of the juices escape.
Transfer the roast, bone side down, to the cooler part of the grill. Cover and grill for 1 hour and 20 minutes to 1 hour and 30 minutes for rare, or longer for more well done meat. After 1 hour, insert an instant-read thermometer in the thickest part of the meat (not too close to the bone). When the thermometer registers 130°F (for rare meat) to 140°F (for medium meat), remove the roast from the grill and let rest for 5 to 10 minutes before carving. Do not overcook. Serve with horseradish cream sauce.