Prime Rib Dip Recipe

Season and roast

Preheat oven to 450°F (230°C). Pat the prime rib roast dry. Rub the roast with olive oil, then evenly coat with kosher salt, black pepper and garlic powder. Place roast on a rack in a roasting pan, fat side up. Roast at 450°F for 15 minutes to develop a crust, then reduce oven temperature to 325°F (165°C) and continue roasting until an instant-read thermometer inserted into the center reads 125°F for medium-rare (about 15–20 minutes per pound). For 2 lbs expect roughly 25–35 minutes after the initial sear; check temperature early. Remove roast and tent loosely with foil; let rest 15–20 minutes (temperature will rise ~5–10°F).

Slice and assemble

While roast rests, slice baguette in half lengthwise and brush cut sides with melted butter. Heat a skillet or griddle over medium heat and toast cut sides until golden, about 2–3 minutes. Thinly slice rested prime rib against the grain into thick slices (about 1/4–1/3 inch). Pile sliced beef onto the bottom baguette, top with provolone slices (arrange so cheese will melt from residual heat). Close sandwich and cut into individual portions. Keep warm, covered, while preparing finishing elements.

In a small saucepan over medium heat, melt 1 tablespoon butter. Add minced shallot and cook until softened and translucent, about 2–3 minutes. Deglaze pan with 1 tablespoon red wine (if using) scraping any brown bits, then add beef stock, Worcestershire sauce and thyme. Bring to a gentle simmer and let reduce slightly for 8–10 minutes to concentrate flavor. If you prefer a slightly thicker jus, mix 1 teaspoon cornstarch with 1 tablespoon cold water to make a slurry and whisk into simmering jus; simmer 1–2 minutes until slightly thickened. Season to taste with salt and pepper. Keep hot and serve in small individual ramekins or a communal dipping cup.

In a small bowl combine 1 cup mayonnaise, 1 tablespoon sour cream, finely chopped rosemary, lemon juice, minced garlic, salt and black pepper. Stir until smooth and adjust seasoning to taste. Refrigerate until service; bring to room temperature briefly before serving if stored cold.

Prepare onions

Peel the onion and slice very thinly into rings (use a mandoline for uniformity). Separate rings into strings and place in a bowl of cold water while you prepare the batter to remove excess starch; drain and pat dry thoroughly.

Make batter

In a bowl whisk together 1 cup all-purpose flour, 1/4 cup cornstarch and 1 teaspoon baking powder with 1 teaspoon kosher salt. In a separate small bowl beat 1 egg lightly; whisk egg and 3/4 cup cold beer into the dry ingredients until a smooth but slightly thick batter forms. Keep batter cold (set bowl over ice if necessary).

Fry onion strings

Heat vegetable oil in a deep-fryer or heavy pot to 375°F (190°C). Working in small batches, toss dried onion rings in a little flour or directly dredge through the batter to coat, then carefully drop into hot oil. Fry until golden brown and crisp, about 2–3 minutes per batch. Use a slotted spoon to transfer to a wire rack or paper towels; immediately sprinkle with 1/4 teaspoon finishing salt. Keep warm and crisp in a low oven (200°F / 95°C) on a rack while finishing sandwich.

Place the toasted prime rib sandwich on a platter or plate. Serve with a small cup of hot au jus for dipping, a ramekin of creamy rosemary sauce, a portion of beer-battered onion strings, and dill pickle slices on the side. To eat, dip thick prime rib slices or sandwich halves into au jus and add creamy rosemary as desired; enjoy with pickles and onion strings.