Beef Tenderloin French Dip Recipe

Season and Rest

Pat the beef tenderloin dry with paper towels. Combine espresso powder, coarsely ground black pepper and kosher salt; rub evenly over the entire surface of the tenderloin. Let sit at room temperature for 30–45 minutes to take the chill off and allow rub to adhere.

Sear and Roast

Preheat oven to 425°F (220°C). Heat 1 tablespoon olive oil and 1 tablespoon neutral oil in a heavy ovenproof skillet over high heat until shimmering. Sear the tenderloin on all sides until well-browned, about 2–3 minutes per side, using tongs to hold ends—total sear time ~8–10 minutes. Transfer skillet to preheated oven and roast until an instant-read thermometer inserted into the center reads 125°F (52°C) for medium-rare, about 10–15 minutes depending on thickness. Remove from oven, transfer beef to a cutting board, tent loosely with foil and rest 10–15 minutes (temperature will rise a few degrees).

Slice

After resting, slice the tenderloin thinly on a bias into 1/8–1/4-inch slices for sandwiches. Keep warm.

While the beef rests, thinly slice the yellow onion. Heat 1 tablespoon unsalted butter in a skillet over medium heat. Add sliced onion and cook, stirring occasionally, until softened and lightly caramelized, about 10–12 minutes. Season lightly with a pinch of salt and set aside and keep warm.

Split the sandwich rolls and brush cut sides lightly with butter. On a griddle or skillet over medium-high heat, toast the rolls cut-side down until golden, about 1–2 minutes. Remove from heat.

Arrange warm beef slices onto the bottom halves of the toasted rolls, dividing evenly among 6 rolls. Top the beef on each sandwich with a slice of provolone; return open-faced sandwiches to a low oven (or under a broiler set to low) just long enough to melt the cheese, about 1–2 minutes—watch closely to avoid burning.

In a small bowl combine 1/2 cup mayonnaise, 2 tablespoons finely chopped fresh chives, 1 teaspoon lemon juice, 1/2 teaspoon Dijon mustard, 1/2 teaspoon minced garlic, 1/4 teaspoon salt and 1/4 teaspoon black pepper. Mix until smooth. Taste and adjust seasoning. Refrigerate until ready to assemble.

Spread about 1 tablespoon of chive aioli on the top halves of each toasted roll just before closing the sandwich.

While beef is roasting, make the au jus: in a medium saucepan over medium heat combine 1 tablespoon tomato paste and 1/2 cup dry red wine (if using). Cook, stirring, 1–2 minutes to reduce and bloom the tomato paste. Add 3 cups beef stock, 1 teaspoon Worcestershire sauce, 2 sprigs fresh thyme and 1 bay leaf. Bring to a simmer and reduce gently until the liquid measures about 1 to 1 1/2 cups and is slightly concentrated, about 15–20 minutes.

Remove thyme sprigs and bay leaf. Taste and adjust seasoning with salt and pepper if needed. For a richer finish, whisk in 1 tablespoon cold unsalted butter, one piece at a time, off the heat to emulsify the sauce. If you prefer a slightly thicker demi-glace, mix 1 teaspoon cornstarch with 1 tablespoon cold water to make a slurry, return sauce to a simmer and whisk in the slurry until it slightly thickens; simmer 1 minute and remove from heat.

Ladle the hot au jus into individual small cups (about 1/3 cup each) for dipping and keep warm until serving.

Spread chive aioli on the top roll halves. Place griddled onion on top of melted provolone and beef. Close sandwiches, garnish with additional chopped chives if desired, and serve immediately with a warm cup of the demi-glace au jus for dipping.

If making ahead for a short time: keep au jus warm gently over low heat; reheat beef slices quickly in a hot skillet for 30–60 seconds before melting cheese and assembling to preserve juiciness.