Tying the roast isn’t necessary, but it helps keep the form of the rib roast for presentation. For the horseradish cream, blend equal parts prepared horseradish with mayonnaise. Gauging the internal temperature of the meat is a key essential; I use both an oven meat probe thermometer with an alert, as well as an instant-read thermometer at the finish. A final temperature of 125ºF will carryover another five degrees which should yield a perfect medium-rare pink. If any of your guests prefer their beef cooked more, the end slices should be cooked to medium.