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Split image showing seasoned roast beef on a tray and a French dip sandwich ready for dipping in delicious Au Jus.

How to Make Delicious Au Jus: A Perfect Sauce for French Dip Sandwiches

Learn to make a rich and savory au jus to elevate your French dip sandwiches. This recipe guides you through preparing the roast, caramelizing onions, and assembling the perfect sandwich with a flavorful dipping sauce.
Prep Time 30 minutes
Cook Time 3 hours
Caramelizing Onions 2 hours
Total Time 5 hours 30 minutes
Servings: 6 sandwiches
Course: Dinner
Cuisine: American
Calories: 509

Ingredients
  

For the Roast Beef
  • 3 pound rump roast
  • 2 tablespoons Montreal seasoning
  • 1 tablespoon olive oil for the roast
For the Caramelized Onions
  • 3 pounds yellow onions sliced into 1/4 inch slices
  • 1 tablespoon olive oil for the onions
  • 1 pinch kosher salt
For the Au Jus and Sandwiches
  • 2 10-ounce cans beef consommé
  • 10 ounces water
  • 1.5 tablespoons sherry
  • 12 slices provolone cheese
  • 6 sturdy hoagie rolls

Equipment

  • Oven
  • Baking sheet
  • Roasting pan
  • Heavy pot or Dutch oven
  • Saucepan
  • Carving knife
  • Tongs
  • Ramekins

Method
 

  1. The day before serving, preheat your oven to 250°F (120°C). Place the rump roast on a baking sheet or roasting pan. Rub it with 1 tablespoon of olive oil, then cover with Montreal steak seasoning, patting it into the meat.
  2. Cook the roast for 2 to 2.5 hours, or until it reaches an internal temperature of 120°F (rare) to 140°F (medium). Remove the roast from the oven and let it cool to room temperature. Cover and refrigerate it. Slicing the meat thinly is easier when it is cold.
  3. Peel and slice the yellow onions into 1/4 inch slices. Heat the remaining 1 tablespoon of olive oil in a heavy pot or Dutch oven over medium heat. Add the sliced onions and a pinch of kosher salt. Stir to combine, cover the pot, and simmer the onions, stirring occasionally, for 1 to 2 hours, or until they are soft and golden.
  4. Transfer the caramelized onions to a storage container and refrigerate until ready to serve.
  5. When ready to assemble the sandwiches, place the cold roast beef on a carving board and slice it very thinly using a sharp carving knife. Set aside.
  6. In a saucepan, combine the beef consommé, water, and sherry. Heat the mixture to a simmer and taste for seasoning. If it is too salty, add a little more water. Keep the au jus warm on a simmer.
  7. Preheat your oven to 350°F (175°C). Split the hoagie rolls lengthwise and place them on a baking sheet. Fill each roll with two slices of provolone cheese and bake for 3 to 5 minutes, or until the cheese just begins to melt.
  8. Reheat the caramelized onions in the microwave for 1 to 2 minutes. Set aside.
  9. Using tongs, transfer about half a pound of the thinly sliced beef to the simmering au jus. Heat the beef for 30 to 40 seconds in the jus. Use the tongs to transfer the beef and pile it onto the prepared hoagie rolls.
  10. Top each sandwich with a scoop of the reheated caramelized onions.
  11. Divide the remaining au jus into 6 ramekins and serve alongside each sandwich for dipping.

Nutrition

Calories: 509kcalCarbohydrates: 56gProtein: 22gFat: 22gSaturated Fat: 10gCholesterol: 39mgSodium: 796mgPotassium: 418mgFiber: 5gSugar: 14gVitamin A: 530IUVitamin C: 16.9mgCalcium: 495mgIron: 11.9mg

Notes

This recipe is designed to create a flavorful au jus that perfectly complements French dip sandwiches. The process involves preparing the roast beef and caramelized onions ahead of time, making assembly quick and easy for serving.

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