Slow Roasted Prime Rib Dinner Recipe

Bring roast to room temperature

Remove the prime rib from the refrigerator 2 to 3 hours before cooking (at least 1 hour per 2 lbs). Pat dry with paper towels. This ensures even cooking.

Preheat oven for slow roast

Preheat the oven to 225°F (107°C). Position a rack in the lower third of the oven to allow even heat circulation.

Make seasoning rub

In a small bowl combine kosher salt, coarsely ground black pepper, garlic powder, chopped rosemary and olive oil to form a paste.

Season the roast

Rub the entire surface of the roast generously with the seasoning paste, pressing it into the fat cap and between bones where accessible. For strongest flavor, season the roast and wrap loosely; refrigerate overnight uncovered if desired, then bring back to room temperature for 2–3 hours before roasting.

Roast low and slow

Place the roast bone-side down (bones as a natural rack) on a roasting pan with a rack. Insert an oven-safe meat thermometer into the thickest part of the eye (away from bone). Roast at 225°F until internal temperature reaches 120°F for rare, 125°F for medium-rare. Plan about 30–40 minutes per pound at this temperature, but rely on thermometer (for a 5 lb roast expect ~2.5–3.5 hours).

Rest and crisp sear (reverse sear)

When roast reaches target internal temp (120–125°F), remove from oven, tent loosely with foil and rest 20–30 minutes. Increase oven temperature to 500°F (or preheat a hot broiler or a hot skillet). Return roast to oven or sear in cast-iron fat-side down to develop a deep brown crust: roast at 500°F for 6–10 minutes, or broil 4–6 minutes, watching carefully to avoid burning. Aim for final internal temps: 125–130°F rare to medium-rare after carryover.

Carve

Transfer to a cutting board. Let rest 10 minutes after the sear then carve between the bones to produce individual rib-eye slices. Slice each portion to desired thickness (1/2"–1" typical). Season slices lightly with salt and pepper if needed.

Collect drippings

After the initial low-and-slow roast (before the high-heat sear), pour pan drippings into a fat separator or a heatproof bowl. Allow fat to rise and skim off excess fat, reserving about 1/4 cup of drippings.

Sauté aromatics

In a medium saucepan over medium heat, add the reserved drippings and the minced shallot. Cook 2–3 minutes until softened and fragrant but not browned.

Deglaze and simmer

Add the dry red wine to deglaze the roasting pan or saucepan, scraping up browned bits. Cook until wine reduces by half (3–5 minutes). Add beef stock, thyme sprigs and bay leaf. Bring to a simmer and reduce gently 10–15 minutes to concentrate flavors.

Finish au jus

Remove thyme sprigs and bay leaf. Taste and season with salt and pepper. Whisk in 1 tablespoon unsalted butter off-heat for a glossy finish. Keep warm until serving; reheat gently if necessary.

Combine prepared horseradish, sour cream, mayonnaise, lemon juice, salt and pepper in a small bowl. Mix until smooth. Adjust horseradish and lemon to taste for desired heat/acidity. Chill until serving.