The Prime Rib Dip Recipe

Season and Rest

Remove the prime rib from the refrigerator 1–2 hours before cooking to come to room temperature. Pat dry with paper towels. Rub the roast with olive oil, then evenly coat with kosher salt, black pepper, and garlic powder. Let rest uncovered while oven preheats.

Slow Roast

Preheat oven to 225°F (110°C). Place the roast on a wire rack set over a roasting pan fat-side up. Insert a meat thermometer into the thickest part, not touching bone. Roast until the internal temperature reaches 120°F (49°C) for medium-rare (about 20–25 minutes per pound; approximately 80–100 minutes for a 4 lb roast). Cooking time will vary by roast size—use temperature, not time, as the guide.

High-Heat Sear

When roast reaches 120°F, increase oven temperature to 475°F (245°C). Return roast to oven and roast 8–12 minutes, until the exterior is browned and the internal temperature reaches 125–130°F (52–54°C) for medium-rare. Remove roast and tent loosely with foil; rest 20–30 minutes. During resting the temperature will rise ~5°F.

Make Au Jus

While the roast rests, pour pan drippings from the roasting pan into a fat separator or skim fat into a saucepan (leave a tablespoon for flavor). Place the roasting pan over two burners (or deglaze a separate skillet) and add the red wine. Scrape browned bits with a wooden spoon and reduce wine by half over medium-high heat (2–3 minutes). Transfer liquid to a saucepan, add beef stock, thyme sprigs, and remaining juices. Bring to a simmer and reduce gently 8–10 minutes to concentrate flavor. Whisk in demi-glace if using and finish with butter for gloss. If you prefer a slightly thicker jus, make a slurry with the flour and cold water and whisk in a little at a time until desired thickness. Strain the jus through a fine-mesh strainer into a serving vessel and keep warm.

Slice Roast

Using a sharp carving knife, thinly slice the rested prime rib against the grain as thin as possible (aim for 1/16–1/8 inch slices). Keep slices warm by covering loosely with foil. Reserve any extra jus and chopped bits for serving.

Prep the mayo spread: In a small bowl combine mayonnaise with prepared horseradish if using. Season to taste with salt and black pepper. This creates a simple horseradish-mayo spread; plain mayo is also acceptable.

Toast the brioche buns: Heat a large skillet or griddle over medium heat. Lightly butter cut sides of each brioche bun with softened butter. Toast buttered sides in the skillet until golden brown, 1–2 minutes. Keep buns warm.

Assemble the dips: Spread about 1–2 tablespoons of the mayonnaise (or horseradish mayo) on the bottom half of each toasted brioche bun. Pile 3–4 ounces (about 85–115 g) of thinly sliced prime rib per sandwich on top of the mayo.

Serve with au jus: Pour 3–4 ounces (about 90–120 ml) of warm au jus into small dipping bowls or cups for each sandwich. Serve prime rib sandwiches immediately with the bowls of au jus on the side for dipping.

Optional finishing: Offer extra horseradish, cracked black pepper, or a sprinkle of flaky sea salt for guests who want more punch. Leftover au jus can be refrigerated and reheated gently.