Prime Rib Recipe

Prep roast

Remove the prime rib from the refrigerator at least 2 hours before cooking to come to room temperature. Pat dry with paper towels.

Season

In a small bowl, combine 2 tablespoons kosher salt, 2 tablespoons freshly ground black pepper, minced garlic, chopped rosemary, and 3 tablespoons olive oil to form a paste. Rub the paste evenly over the entire surface of the roast, including the exposed bone. Let rest for 30 minutes to absorb flavors.

Sear (optional)

Preheat oven to 500°F (260°C). Place roast fat-side up in a roasting pan with a rack. Roast at 500°F for 15 minutes to develop a crust, then immediately reduce oven temperature to 325°F (160°C).

Roast to temperature

Continue roasting at 325°F until internal temperature reaches 120°F (49°C) for rare, 125°F (52°C) for medium-rare, or 135°F (57°C) for medium; this will take roughly 12-15 minutes per pound depending on oven and roast size. For a 4 lb roast, plan ~50–60 minutes after initial sear, but rely on an instant-read thermometer.

Rest

Remove roast from oven, transfer to a cutting board tented loosely with foil, and rest for 20–25 minutes. Internal temperature will rise about 5–10°F while resting. Reserve pan drippings for au jus.

While the roast cooks or rests, heat 1 tablespoon olive oil and 2 tablespoons butter in a wide skillet over medium-low heat. Add the thinly sliced onions and 1 teaspoon kosher salt. Cook slowly, stirring every few minutes, until the onions are deeply golden and softened, 35–45 minutes. If onions begin to stick, deglaze with 1–2 tablespoons water. Stir in 1 teaspoon granulated sugar about halfway through to encourage caramelization.

When onions are deeply caramelized, stir in 1 tablespoon balsamic vinegar and cook 1–2 minutes more. Taste and adjust seasoning. Keep warm until plating.

Preheat oven to 425°F (220°C) if not already in use. Toss 12 oz mixed mushrooms with 1 tablespoon olive oil, 1 tablespoon melted butter, 1 teaspoon fresh thyme leaves, 1 teaspoon salt, and 1 teaspoon black pepper on a rimmed baking sheet in a single layer.

Roast for 12–18 minutes, stirring once halfway through, until mushrooms are browned and liquid has mostly evaporated. Remove and keep warm.

Preheat broiler. Lightly butter one side of each rye slice. Place buttered-side down on a baking sheet. Top each slice with a generous mound of grated aged Gruyère (about 1/4 cup per slice). Broil 2–4 inches from the heat for 2–4 minutes until cheese is bubbly and lightly browned — watch closely to avoid burning.

Alternatively, toast rye slices in a skillet over medium heat buttered side down, then top with gruyère and cover until melted.

While roast rests, make the au jus: Pour pan drippings from the roasting pan into a fat separator or skim fat with a spoon (reserve about 1 tablespoon fat in pan). Place roasting pan over medium heat on stovetop (or use a saucepan) and add the minced shallot; sauté briefly in the reserved fat until translucent, about 1 minute.

Add 1 tablespoon red wine (optional) to deglaze, scraping up browned bits. Add 3 cups beef or veal stock, 2 sprigs thyme, and 1 bay leaf. Bring to a simmer and reduce by about 1/3, 6–10 minutes, until flavors concentrate.

Strain into a small saucepan, discard solids. Off heat, whisk in 2 tablespoons cold unsalted butter until glossy. Season with 1 teaspoon salt and 1/2 teaspoon black pepper to taste. Keep warm.

Slice prime rib against the grain into 1/2-inch to 3/4-inch thick slices. Place a toasted rye slice on each plate, top with a slice of prime rib, a spoonful of caramelized onions and a generous spoonful of roasted mushrooms. Spoon warm au jus into a small serving vessel or lightly spoon a little jus over the meat.

Finish with a light sprinkle of coarse sea salt and chopped fresh parsley. Serve remaining au jus on the side.