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French dip sandwiches wrapped in aluminum foil with au jus on the side.

French Onion French Dip Sandwiches

Ashley Manila
French Onion French Dip Sandwiches are perfect for dinner. Featuring tender caramelized onions, rare roast beef, and tons of gooey cheese, it's everything you love about French onion soup, but in sandwich form. Use deli roast beef or get fancy and roast your own then slice it up, your call!
5 from 6 votes
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Prep Time 15 minutes
Cook Time 40 minutes
Course Dinner, Lunch
Cuisine American
Servings 4 sandwiches

Ingredients
 

  • 1 long French baguette
  • 1 and 1/2 pounds (340g) rare roast beef thinly sliced
  • 3 Tablespoons (42g) unsalted butter
  • 1 teaspoon fresh thyme leaves finely chopped
  • 3 large yellow onions peeled and thinly sliced
  • 1/2 teaspoon salt
  • 1/2 teaspoon black pepper
  • 1/4 teaspoon red pepper flakes
  • 1/2 cup (113ml) cooking sherry
  • 2 cups (454ml) beef stock
  • 1/2 teaspoon cornstarch
  • 1 teaspoon water
  • 10 ounces Gruyere cheese grated

Instructions
 

  • Slice the baguette into 4 pieces. Then slice each piece of baguette in half, taking care to only cut 3/4 of the way through the bread. 
  • Preheat the oven to 500 degrees(F). 
  • Divide the roast beef evenly among the bread, filling each roll with a 1/4 of the roast beef. Place each piece of baguette on top of a piece of aluminum foil, then set aside.
  • In a large skillet, melt the butter over medium heat. Add the thyme and onions, stir well to coat, then cook on, stirring occasionally, for about 20 to 25 minutes, or until soft and golden in color.
  • Add the crushed salt, pepper, and crushed red pepper and stir to combined. Cook for 2 minutes, then stir in the sherry. Cook for 3 to 4 minutes, stirring occasionally, or until the onions have soaked up the sherry.
  • Add the beef stock and increase the heat to medium-high. Allow the mixture to come to a boil, then reduce the heat to a simmer and cook for another 5 minutes. 
  • Mix the cornstarch with a teaspoon of water to form a slurry, then add it to the onion mixture. Cook for another minute or two, allowing the “au jus” to thicken up just a bit. 
  • With the heat still on simmer, use a slotted spoon to scoop the onions out of the broth, and place them in a large serving bowl. Divide the au jus into individual ramekins for dipping.
  • Divide the onions and shredded cheese evenly on top of the sandwiches, placing the cheese on first, then the onions.
  • Wrap the foil around each sandwich, place them on a baking sheet, and place the baking sheet in the oven for 5 minutes.
  • Carefully remove the pan from the oven, unwrap the sandwiches, and serve at once, with au jus on the side.

Video

Keyword sandwiches, sandwich, french dip, roast beef
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