Directions
Step 1: Mix the mustard, salt, oil, thyme, garlic and pepper and rub it all over the prime rib before pressing the dried mushrooms onto the roast.
Step 2: Place the beef in an oven safe roasting dish with the bones on the bottom and the fat cap on the top, stick a meat thermometer into the middle of the thickest part, roast in a preheated 450F oven for 15 minutes, reduce the temperature to 275 and continue roasting until the temperature reaches the desired doneness (135F for medium rare, about 2 hours). Note: The temperature of the roast will continue to rise a few degrees while resting.
Step 3: Remove the roast from the oven and set aside to rest, covered for 20 minutes before slicing.
Step 4: Meanwhile, drain all but 2 tablespoons of the dripping from the pan, place the pan over medium heat, add the red wine, deglaze the pan, add the beef broth and Worcestershire sauce and simmer for 5 minutes before seasoning with season with salt and pepper to taste.