Sandra Lee of the Food Network has an easy recipe for prime rib au jus. This recipe takes about two and a half hours to cook, but the preparation only takes about 10 minutes.
To make prime rib au jus, preheat the oven to 350 degrees, and then using a paring knife, make a series of small slits into a 4- to 5-pound rib roast. Make these slits about 3 inches apart and in each slit, place a sliver of garlic. With a pastry brush, coat the roast with 2 tablespoons of spicy brown mustard. On top of the mustard, use a peppercorn and garlic marinade, place the roast in a pan and cook it until it is 130 F in the center. Remove the roast, cover it with foil and allow it to rest for about 10 to 15 minutes.
To make the au jus for the roast, place the roasting pan over the stove burners, and set them to a medium-low heat. Whisk in 2 teaspoons of Worcestershire sauce and 1/2 cup of wine while scraping up the brown pieces from the bottom of the pan. Reduce this mixture with heat, and then add a cup of beef broth. Bring this to a simmer, and then again, reduce slightly. Slice the roast, and serve hot with the au jus for dipping.