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Split image showing sliced roast beef with au jus and a French Dip sandwich ready for dipping.

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

Learn to make a rich, savory au jus perfect for French dip sandwiches. This recipe guides you through caramelizing onions and preparing tender roast beef for a truly satisfying meal.
Prep Time 30 minutes
Cook Time 2 hours 30 minutes
Caramelizing Onions 2 hours
Total Time 5 hours
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 Caramelized Onions
  • 3 pounds yellow onions sliced into 1/4 inch slices
  • 1 tablespoon olive oil
  • 1 pinch kosher salt
For the Au Jus and Sandwiches
  • 2 10-ounce cans beef consommé
  • 10 ounces water
  • 1 1/2 tablespoons sherry
  • 12 slices provolone cheese
  • 6 sturdy hoagie rolls

Equipment

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

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 and cover it with Montreal steak seasoning, patting the seasoning into the meat.
  2. Cook the roast for 2 to 2 1/2 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 the yellow onions and slice them into 1/4-inch thick slices. Heat the remaining 1 tablespoon of olive oil in a heavy pot or Dutch oven with a tight-fitting lid over medium heat. Add the sliced onions and a pinch of kosher salt. Stir to combine, place the lid on the pot, and simmer the onions, stirring occasionally, for about 1 to 2 hours, or until they are soft and golden.
  4. Transfer the caramelized onions to a storage container and refrigerate them until ready to serve.
  5. When ready to assemble the sandwiches, place the cold roast beef on a carving board. Use a very sharp carving knife to slice the beef very thinly. 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 for your preference, add a little more water. Keep the au jus 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. Place the rolls in the oven for 3 to 5 minutes, or until the cheese just starts 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 and pile the beef 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 and delicious French dip sandwiches. The caramelization of onions and the slow cooking of the roast beef contribute to the depth of flavor. Adjusting the saltiness of the au jus with water ensures it suits your taste.

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