A standing beef rib roast is sometimes called "prime rib." Prime, however, refers to the grading of the meat and not the specific cut. The USDA grades beef as prime, choice or select depending on its tenderness, flavor and juiciness. Prime beef is generally reserved for restaurants and is available to consumers only in premium butcher shops. You can prepare this recipe using any good-quality standing rib roast.Here, we serve the roast with savory Yorkshire pudding. It is made from the same batter as popovers, but instead of being poured into individual cups, it is prepared as one large soufflelike bread. The key to a good Yorkshire pudding is to have both the pan and the fat very hot when you pour in the batter. This immediately cooks the batter as it comes into contact with the pan and puffs up the pudding nicely. Serve Yorkshire pudding immediately after removing it from the oven, as it will quickly deflate.