Oven Roast Beef with Rosemary Mushroom Sauce

The grainy mustard adds both texture and flavour to the outer crust of this roast recipe. These time-test results are based on a roast that was about 7½-in (19 cm) long x 3¾-in (9.5 cm wide) x 4¾-in (12 cm) deep. NOTE: ‘Time-to-cook’ figures are rough guidelines only as cook time is dependent on so many factors such as oven and thermometer accuracy, starting temperature of roast, roast shape and cut. A good thermometer is one of your best kitchen investments.
Yield 10 Servings Prep. Time 15 min Cooking Time 240 min Total Time 255 min


Here are the following ingredients:

  • 4 lb (2 kg) Beef Outside Round Oven Roast
  • 3 tbsp (45 mL) grainy Dijon mustard
  • 1½ tsp (7 mL) chopped fresh rosemary (or ½ tsp/2 mL crushed, dried rosemary)
  • ¼ tsp (1 mL) EACH salt and fresh ground pepper

Rosemary Mushroom Sauce

  • 1 pkg (1/2 oz/14 g) dried mushrooms (such as porcini, cèpes or cremini)
  • 1 cup (250 mL) boiling water
  • 1 tbsp (15 mL) vegetable oil
  • 1 onion, diced
  • 1 lb (500 g) mixed fresh mushrooms (such as chanterelles, cremini, oyster), coarsely chopped
  • ½ tsp (2 mL) EACH salt and fresh ground pepper
  • 1½ tsp (7 mL) chopped fresh rosemary (or ½ tsp/2 mL crushed, dried rosemary)
  • 1½ cups (375 mL) beef stock or broth
  • ⅓ cup (75 mL) cold water
  • 2 tbsp (30 mL) all-purpose flour
  • ¼ cup (60 mL) minced fresh parsley

Shopping List

Here are the following shopping items to buy:


Follow these cooking methods/directions:

  1. Pat roast dry with paper towel and pierce all over with a fork. Combine mustard, rosemary, salt and pepper in a small bowl. Brush all over roast.

  2. Place roast on rack in shallow roasting pan. Insert oven-safe meat thermometer into centre of roast. Roast, uncovered, in preheated 275°F oven for about 4 hours for medium-rare (145°F/63°C for medium-rare, or 160°F/71°C for medium, or 170°F/77°C for well-done).

  3. Rosemary Mushroom Sauce: Meanwhile, soak dried mushrooms in boiling water in a heatproof bowl for about 10 minutes or until softened. Drain, reserving soaking liquid. Chop soaked mushrooms; set aside.

  4. Heat oil over medium-high heat in a large skillet; cook onion, stirring, for 3 minutes or until softened. Add fresh mushrooms, salt and pepper; cook, stirring, for about 8 minutes or until golden brown and liquid evaporates. Set aside.

  5. Transfer roast to cutting board, cover with foil and let rest for 15 minutes.

  6. Meanwhile, drain off fat from pan drippings. Add reserved mushroom soaking liquid, soaked dried mushrooms, rosemary and beef stock to pan drippings; bring to a boil over medium-high heat, stirring and scraping up brown bits stuck to pan. Gradually stir cold water into flour in a small bowl until smooth; gradually whisk into pan. Boil, whisking, for about 4 minutes or until thickened. Stir in cooked mushroom mixture and parsley. Heat through.

  7. Carve roast across the grain into very thin slices and serve with piping hot mushrooms sauce.