The New York Dip Recipe

Heat a skillet over medium heat and add 1 tablespoon butter and 1 teaspoon olive oil. When the butter melts, add the thinly sliced onion and spread into an even layer.

Cook the onions, stirring every 2–3 minutes, until softened and beginning to brown, about 8–10 minutes.

Add 2 tablespoons balsamic vinegar and 1 teaspoon brown sugar, stir to combine. Reduce heat to medium-low and continue to cook, stirring occasionally, until onions are deeply caramelized, about 6–8 more minutes.

Season with 1 teaspoon kosher salt and 1 teaspoon freshly ground black pepper. Remove from heat and set aside. Taste and adjust seasoning if necessary.

In a small saucepan combine 2 cups beef au jus or low-sodium beef broth, 1 tablespoon dry red wine (if using), 1 teaspoon Worcestershire sauce and 1 minced garlic clove.

Bring the mixture to a gentle simmer over medium heat and let reduce slightly for 6–8 minutes to concentrate flavor.

Season with 1/2 teaspoon salt and 1/4 teaspoon black pepper. Whisk in 1 tablespoon cold butter off the heat to add a glossy finish. Keep warm on the lowest heat setting or transfer to a small serving bowl for dipping.

Prepare the bread

Preheat oven to 375°F (190°C). Slice the everything baguette lengthwise, leaving a hinge if desired. Brush the cut sides lightly with 1 teaspoon olive oil (or spread 1 tablespoon softened butter for extra richness).

Toast the baguette

Place the baguette halves cut-side up on a baking sheet and toast in the oven until the edges are golden and slightly crisp, about 6–8 minutes.

Warm the prime rib

While bread toasts, warm the sliced prime rib gently. Heat a skillet over medium-low, add the sliced beef in a single layer and warm for 1–2 minutes per side just until warmed through (do not overcook). Alternatively, wrap beef in foil and place in the warm oven for 4–6 minutes.

Build the sandwich

Spread 3 tablespoons prepared horseradish evenly on the bottom half of the toasted baguette (adjust to taste). Pile the warmed prime rib onto the bottom half (about 12 oz total). Spoon the caramelized balsamic onions over the beef, distributing them evenly.

Add cheese and finish

Top the beef and onions with 6 oz gruyère. Close the sandwich with the top half of the baguette. If you prefer the cheese melted, return the assembled sandwich to the oven at 375°F (190°C) for 3–5 minutes or place under a broiler for 30–60 seconds watching closely, until the gruyère is melted and bubbly.

Serve

Remove from oven and let rest 1 minute. Slice the sandwich into 2–3 portions. Serve immediately with a small bowl of warm au jus for dipping and garnish with chopped parsley if desired.

Make sure au jus is warm at serving temperature. Provide extra horseradish at the table for guests who want more heat. Optionally spoon a little au jus over the meat in the sandwich before closing for extra juiciness.