French Dip Recipe

Heat a large skillet over medium-low heat. Add 1 tablespoon butter and 1 teaspoon olive oil so the butter doesn’t burn.

Add the thinly sliced onions and 1/4 teaspoon kosher salt. Cook, stirring occasionally, for about 20–30 minutes until the onions are deep golden brown and soft. If they begin to stick or brown too quickly, lower the heat and add 1–2 tablespoons water to deglaze the pan.

Stir in 1 teaspoon sugar about halfway through to encourage caramelization. When onions are deeply caramelized, remove from heat and set aside.

If you have roast pan drippings, skim off excess fat leaving about 1 tablespoon. In a small saucepan over medium heat, add 2 cups beef drippings or pan juices and 1 cup low-sodium beef broth.

Add 1 tablespoon minced shallot, 1 crushed garlic clove, 1 sprig fresh thyme, 1 teaspoon Worcestershire sauce and 1/4 cup dry red wine (optional). Bring to a gentle simmer and reduce for 6–8 minutes to concentrate flavor.

Taste and season with 1/2 teaspoon salt and 1/4 teaspoon black pepper. If you prefer a slightly thicker jus, mix 1 teaspoon cornstarch with 1 teaspoon cold water to make a slurry, whisk into simmering jus and cook 1–2 minutes until slightly thickened.

Strain the jus through a fine-mesh sieve into a heatproof bowl or small pitcher and keep warm.

In a small bowl combine 1/2 cup mayonnaise, 1 tablespoon prepared horseradish, 1 teaspoon Dijon mustard, 1 teaspoon fresh lemon juice and 1/2 teaspoon minced garlic.

Season with 1/4 teaspoon salt and 1/8 teaspoon black pepper. Taste and adjust horseradish (add up to another 1/2 teaspoon) or lemon as desired. Refrigerate until ready to assemble.

Preheat oven to 350°F (175°C). If roast ribeye is not already cooked: season a 1 lb roast ribeye with 1 teaspoon kosher salt and 1 teaspoon black pepper and roast to desired doneness (rare-medium-rare recommended). Allow to rest 10 minutes, then thinly slice across the grain. (If using leftover roast, slice thinly and reheat gently in the au jus later.)

Slice the baguette in half lengthwise. Lightly brush the cut sides with the softened 2 tablespoons butter.

Arrange a layer of provolone slices on the bottom half of the baguette. Toast the buttered baguette halves in the oven on a baking sheet for 5–7 minutes until the cheese melts and bread is lightly golden.

While bread is toasting, warm the sliced ribeye: heat a skillet over medium, add 1 tablespoon olive oil, add slices of roast and sear briefly 30–60 seconds per side just to heat through (or warm in the au jus for a minute).

Remove toasted baguette from oven. Spread a generous layer of horseradish aioli on the top half of the baguette. Pile warmed sliced ribeye onto the cheese-covered bottom half, top with a generous portion of caramelized onions, then close the sandwich and press lightly.

Cut the sandwich into portions (3–4 pieces) and serve immediately with a small bowl or cup of warm au jus for dipping.