Nothing gets your guests' attention like a juicy prime rib roast.
Cut shallow slits all over roast; insert garlic slivers into slits.
Rub all over with Worcestershire sauce, salt and pepper.
Combine parsley, mustard, thyme and oil into bowl and rub all over roast.
Place roast (bones down) on rack in shallow roasting pan. Insert oven-safe meat thermometer into centre of the roast.
Roast uncovered in 450F (230C) oven for 10 minutes.
Reduce heat to 275F (140C); roast until thermometer reads 135F (57C) for medium-rare to medium, about 2 3/4 to 3 1/4 hours. Remove from oven.
Cover loosely with foil and let stand for 15 to 30 minutes before carving.