- One well-aged 15-to 18-pound standing rib roast (about 7 ribs), chine bone removed, trimmed of excess 101 and tied
- Sea salt
- Freshly ground black pepper
- 6 cloves garlic, peeled and very thinly sliced
- 36 small boiling or cipollini onions, peeled and left whole
- 36 new (baby) potatoes, left whole, or 12 larger potatoes, peeled and quartered
- 4 heads garlic, ¼ inch cut off the top to just expose the cloves
- ¼ cup minced fresh thyme
- Place a rack in the middle of the oven and preheat to 450 degrees F.
- Season the beef liberally all over with salt and pepper. Using a small, sharp knife, make several small slits in the fat along the top of the beef and gently insert the garlic slices. Place the beef fat-side up on a roasting rack in a large roasting pan. Roast the beef for 20 minutes.
- Place the onions, potatoes, and garlic in a bowl and toss with salt, pepper, and the thyme.
- Reduce the oven temperature to 325 degrees F and continue roasting for 2 hours. Arrange the vegetables around the beef, in the bottom of the roasting pan. Roast for another 1 to 2 hours, until the internal temperature of the meat reaches 140 degrees F for medium-rare. Stir the vegetables well to coat with any juices collected on the bottom of the roasting pan and baste the beef and the vegetables once or twice during the final hour of roasting so they brown evenly.
- Remove from the oven and place on a carving board or wooden board; cover loosely with foil for 15 minutes before carving to let the meat juices settle. Remove the excess fat from the pan juices by tipping the roasting pan to the side and spooning off the fat that rises to the top.
- Carve the beef. You can serve everyone a whole rib or slice the meat off the ribs for a smaller portion. Serve with the potatoes, onions, and garlic (popped out of the skins), with the pan juices spooned on top.