Step 1

Preheat the oven to 350 F.

Step 2

Allow the prime rib to sit at room temperature while you prep the vegetables. Remove the skin from the garlic cloves and slice the garlic. Break up 1 sprig of rosemary into small pieces. Slice the yellow onion and shallot into thin, small slices. Chop the thyme and remaining rosemary.

Step 3

Cut small slits into the prime rib. Make slits all over the roast, and then stuff each hole with a piece of garlic and a small piece of rosemary. Season the meat well with salt and pepper.

Step 4

Place the meat in a roasting pan or Dutch oven and allow to cook. Cook for approximately 2 hours, or until the meat comes up to the proper temperature. For medium-rare, cook until a meat thermometer reads 130 to 135 F. Once cooked, remove the meat from its pan, place it on a cutting board or serving platter, and cover with tin foil to keep warm.

Step 5

To make the thick au jus, utilize the roasting pan, complete with the dripping from the meat for flavor. Sauté the thinly sliced onion and shallot. Scrape the drippings on the sides and bottom of the pan. Then, add the wine and cook on the stovetop on high heat until it reduces. Once reduced, add the beef stock, and then whisk in thyme and rosemary, and season with salt and pepper. Allow to reduce by half.

Step 6

Slice the roast and serve with thick au jus.