Adapted from americanfood.about.com
standing beef rib roast (4 to 7 ribs, 9 to 18 pounds)
fresh course-ground black pepper, as needed
kosher salt (or other larger grain, flake-style salt), ½ teaspoon per bone
softened butter, ½ tbsp per rib of beef
large metal roasting pan with at least 3-inch sides.
quart cold beef broth
Remove the prime rib from the refrigerator and place in the pan. No rack is needed as the rib bones form a natural rack, and will keep the prime rib off the pan. Rub the entire surface of the cold roast with butter, and coat evenly with the kosher salt and black pepper. Leave the prime rib out at room temperature for 2 hours. Preheat the oven to 450 degrees F. When the oven is hot, put the roast in and cook for 20 minutes to sear the outside of the roast. After 20 minutes turn the oven down to 325 degrees F. and roast until the desired internal temperature is reached (see guide below). For medium-rare this will take approximately 15 minutes per pound. Transfer to a large platter, and let the prime rib rest, loosely covered with foil for 30 minutes before serving. Cutting into the meat too early will cause a significant loss of juice. To Make the "Au Jus" Sauce While the prime rib is resting, pour off all but 2 tablespoons of the fat from the pan and place on the stovetop over medium heat. Add the flour and cook, stirring, for 5 minutes to form a roux. Pour in the beef broth and whisk into the roux, scraping all the caramelized beef drippings from the bottom of the pan. Turn heat to high and cook the sauce for 10 minutes until it reduces and thickens slightly (this is not a gravy, so don't expect a thick, heavy sauce). Adjust seasoning, strain and serve along side the prime rib. Internal Temperature Guide Below are the internal temperatures to go by, depending on how done you like your prime rib. Remember, these are the temperatures to remove the beef, and not the final temperature. The roast will continue to cook after it's removed. Rare: remove at 110 degrees F. (final temp about 120) Medium-Rare: remove at 120 degrees F. (final temp about 130) Medium: remove at 130 degrees F. (final temp about 140)