French Dip Recipe

In a small bowl, whisk together mayonnaise, prepared horseradish, lemon juice, Dijon mustard, kosher salt, and black pepper until smooth. Taste and adjust horseradish or salt to preference. Refrigerate until ready to assemble.

Combine Greek yogurt, mayonnaise, minced garlic, olive oil, lemon juice, salt, and black pepper in a bowl. Whisk until smooth and creamy. Refrigerate to let flavors meld while preparing the rest of the sandwich.

In a medium saucepan over medium heat, add beef broth and optional red wine. Bring to a gentle simmer.

Stir in beef base (or demi-glace), soy sauce or Worcestershire sauce, smashed garlic clove, and fresh thyme. Simmer gently for 10–15 minutes to concentrate the flavors, skimming any foam.

Remove the thyme sprig and garlic. Taste and season with salt and pepper. Whisk in 1 tablespoon unsalted butter off the heat for a glossy finish. Keep the au jus warm on the lowest stove setting; keep covered.

Preheat oven to 375°F (190°C) or heat a skillet over medium-high heat if using the stove-top method.

If rolls are large, split them and lightly butter the cut sides with the 2 tablespoons of unsalted butter.

In a skillet or on a baking sheet, toast the buttered cut sides until golden and crisp (about 2–4 minutes under the broiler or 1–2 minutes in a skillet). Remove from heat.

Warm the roast beef gently: place the sliced roast beef in a skillet over medium-low heat just until warmed through (about 2–3 minutes) or briefly heat slices in the oven wrapped in foil for 4–6 minutes. This prevents overcooking while ensuring juicy meat.

On the bottom halves of each toasted roll, spread a generous layer of horseradish mayo. On the top halves, spread a thin layer of garlic sauce (optional: serve extra on the side).

Divide the warmed roast beef among the rolls, piling approximately 4 ounces (about 113 g) per sandwich. Top the beef with two slices of Swiss cheese per sandwich.

If you prefer the cheese melted, place assembled open-faced sandwiches under a broiler or in a hot oven (375°F/190°C) for 1–2 minutes until the cheese melts and bubbles. Watch closely to avoid burning.

Close the sandwiches. Slice each sandwich in half if desired. Serve immediately with a small bowl of warm au jus for dipping and optional pickles and chopped parsley on the side.