Preheat the oven to 350º F.
Lay the beef in a large roasting pan with the bone side down. The ribs act as a natural roasting rack.
In a small bowl mash together the garlic, horseradish, rosemary, thyme, salt, pepper, and olive oil to make a paste. Massage the paste generously over the entire roast.
Put the pan in the oven and roast the beef until the internal temperature of the meat registers 125º F on an instant-read thermometer (medium-rare), 1 1/2 to 2 hours.
Remove the beef to a carving board and let it rest for 20 minutes before carving.
If roast is bigger than 6 pounds cook 15-20 min. per pound.