Christmas Prime Rib of Beef Here is the prime rib and Yorkshire pudding recipe that has been requested. Makes me hungry for a good feed. For the beef to qualify it has to be free of bruises, evenly marbled steer meat, dry aged for at least 29 days and a one inch thick fat cap is also required. Start by rubbing a spice mixture which contains equal amounts of kosher salt, garlic powder, beef base, ground black pepper, keens mustard powder and mild paprika. The spice rub is most important to making a tender roast. Massage this mixture all over the room temperature beef until...