Open-Faced Roast Beef Sandwich with Caramelized Onions

In this recipe, the onions slowly cook and caramelize in the oven with the roast resulting in a delicious sauce with all the flavours of classic French onion soup. You can scale up the cheese option to a Gruyère or Emmental, if you like. 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 8 Servings Prep. Time 15 min Cooking Time 105 min Total Time 120 min


Here are the following ingredients:

  • 2 tbsp (30 mL) finely chopped fresh thyme
  • 3 cloves garlic, minced
  • 4 tsp (20 mL) olive oil
  • 1 tsp (5 mL) EACH salt and fresh ground pepper
  • 3 lb (1.5 kg) Beef Inside Round Oven Roast

Caramelized Onions

  • 3 tbsp (45 mL) butter, melted
  • 5 cups (1.25 L) thinly sliced onions (about 1½ lb/750 g)
  • ½ tsp (2 mL) EACH salt and fresh ground pepper

Pan Sauce

  • 3 tbsp (45 mL) butter, divided
  • 3 tbsp (45 mL) all-purpose flour
  • 1 cup (250 mL) dry red wine
  • 2 cups (500 mL) reduced-sodium beef broth
  • 2 tbsp (30 mL) Worcestershire sauce
  • 2 sprigs fresh thyme
  • 2 bay leaves
  • 2 tbsp (30 mL) finely chopped fresh chives


  • 8 thick slices sourdough bread
  • 2 tbsp (30 mL) butter
  • 16 slices Swiss cheese

Shopping List

Here are the following shopping items to buy:


Follow these cooking methods/directions:

  1. Combine thyme, garlic, oil, salt and pepper in a small bowl. Pat roast dry with paper towel and rub thyme mixture all over roast.

  2. Place roast on rack in shallow roasting pan. Insert oven-safe meat thermometer into centre of roast. Place on middle rack of the oven. Oven-sear roast in preheated 450°F oven for 10 minutes.

Caramelized Onions :
  1. Meanwhile, toss melted butter with onions, salt and pepper in a large bowl. Arrange evenly on large baking sheet. Transfer to oven on the rack above the roast in the top-third of oven.

  2. Reduce heat to 275°F; roast, uncovered and stirring onions occasionally, for about 1¼ to 1¾ hours until onions are tender and roast is cooked to medium-rare, removing from oven when 5°F (3°C) below desired finished temperature (145°F/63°C for medium-rare, or 160°F/71°C for medium, or 170°F/77°C for well-done). NOTE: See ‘AVERAGE ROAST COOKING TIMES’ chart below for timing estimates for all types and sizes of beef roasts.

  3. Transfer roast to a cutting board, cover with foil and let rest for 15 minutes. Set Caramelized Onions aside.

Pan Sauce :
  1. Meanwhile, melt butter in roasting pan over medium heat. Sprinkle with flour; cook, stirring for 2 to 3 minutes or until smooth. Gradually whisk in red wine; bring to a boil, stirring and scraping up any browned bits from pan. Stir in broth, Worcestershire sauce, thyme sprigs and bay leaves; bring back to a boil. Stir in Caramelized Onions and reduce heat to medium-low. Simmer, stirring occasionally, for 10 to 15 minutes or until sauce is thickened and flavours are blended. Remove thyme sprigs and bay leaves; discard. Stir in chives.

  2. Carve roast across the grain into thin slices.

  1. Place bread slices on a foil-lined baking sheet. Broil for 1 to 2 minutes per side or until golden and toasted. Spread butter on bread slices and top each with 2 cheese slices. Broil for 1 minute or until cheese starts to melt.

  2. Place each slice of bread in a shallow bowl or pasta plate. Top with sliced beef and top with gravy.

Roast Cooking Chart