Prime Rib with Mustard and Rosemary Crust

With a simple mustard and herb seasoning, the wonderful beefy flavour of prime rib really shines. Searing the roast in a hot oven and then cooking it low and slow does take a little longer but it seals in every drop of juice keeping it melt-in-your-mouth tender. A good meat thermometer is worth the investment to make sure you get an accurate test for doneness. The slow roasting method reduces the quantity of pan drippings so the flavour of the jus relies on good-quality stock. Use homemade stock if you have it or the highest-quality prepared stock available. If you prefer a thickened gravy, stir 2 tbsp (25 mL) all-purpose flour into the onions and cook for a minute before adding the stock.

5 lbs (2.2 kg) beef prime rib premium
oven roast
½ cup (125 mL) grainy or Dijon mustard
2 tbsp (25 mL) chopped fresh rosemary,
or 2 tsp (10 mL) dried
1 tsp (5 mL) salt
1 tsp (5 mL) coarsely ground pepper

Rosemary Jus

1 small onion, finely chopped
1 tsp (5 mL) finely chopped fresh rosemary,
or ¼ tsp (1 mL) dried
2 cups (500 mL) beef stock
1 tsp (5 mL) grainy or Dijon mustard
Salt and freshly ground pepper to taste

1. Preheat oven to 450°F (230°C).

2. Place roast rib-side down in roasting pan. Combine mustard, rosemary, salt and pepper. Rub over top and sides of roast.

3. Roast for 10 minutes. Turn heat down to 275°F (140°C).

4. Roast rib for 3 to 3½ hours or until meat thermometer reads 135°F (57°C) for mediumrare, 4 hours or until meat thermometer reads 145°F (62°C) for medium or until desired doneness. Place roast on cutting board and tent with foil for 20 minutes.

5. To make jus, place pan over medium heat and stir in onions and rosemary; sauté for about 3 minutes or until soft. Stir in beef stock and mustard and bring to a boil, scraping up any bits stuck to pan. Simmer, stirring often, for about 5 minutes or until slightly reduced. Season with salt and pepper to taste. Pour into a warmed gravy boat. Serve slices of roast drizzled with jus.

Serves 8