Ingredients

2.5 kg / 5 lb standing rib roast / prime rib, bone in

1 onion, unpeeled, quartered (brown, yellow, or white)

1 head of garlic, unpeeled, halved horizontally

5 sprigs thyme

3 sprigs rosemary

150g / 10 tbsp unsalted butter, softened

5 garlic cloves, minced

2 tsp finely chopped fresh rosemary (or 1 tsp dried)

2 tsp finely chopped fresh thyme (or 1 tsp dried)

2 tsp salt

1 tsp black pepper

1 1/2 cups low salt beef broth/stock

2 1/2 cups dry red wine

1 tbsp cornflour/cornstarch (optional)

Instructions

Step 1: Take the beef out of the fridge 2 to 3 hours before cooking to bring it to room temperature. Pat dry with a paper towel for even cooking.

Step 2: Preheat your oven to 240°C / 460°F (220°C fan). Adjust the oven rack so the beef will sit in the middle.

Step 3: Mix the softened butter with the minced garlic, chopped rosemary, thyme, salt, and black pepper to make the garlic herb butter.

Step 4: In a heavy-based ovenproof skillet or roasting pan, place the quartered onion, halved head of garlic, and the thyme and rosemary sprigs to create a roasting bed.

Step 5: Spread a thin layer of the herb butter on the underside (bone side) of the beef. Place the beef butter side down on the roasting bed, then spread about two-thirds of the remaining butter over the top and sides of the roast. Reserve the rest for later.

Step 6: Roast the beef in the hot oven for 20 minutes to sear the outside and lock in flavors.

Step 7: Remove the beef and spread the reserved butter all over the top and sides. Lower the oven temperature to 120°C / 250°F (100°C fan).

Step 8: Return the roast to the oven for a slow roast of about 1 1/2 hours. Baste every 30 minutes with the pan juices. Start checking the internal temperature early, aiming for 51°C / 123.8°F in the center for medium rare.

Step 9: Once done, transfer the beef to a plate and loosely cover with foil. Rest for 20 to 30 minutes. During this time, the internal temperature will rise to 56-58°C / 133-136.4°F, perfect for medium rare.

Step 10: Slice the beef and serve with the accompanying red wine sauce. For a classic steakhouse meal, accompany with Paris mash and garlic sautéed spinach.

Step 11: To make the red wine sauce, place the skillet with the onion and garlic over high heat on the stove. Add the red wine and beef stock, and simmer rapidly for about 10 minutes until the liquid reduces by two-thirds to approximately 1 1/2 cups.

Step 12: Lower the heat to medium. Mix cornflour with 2 tablespoons of water. Gradually drizzle in half the mixture into the simmering sauce, stirring until thickened (about 1 minute). Add more cornflour mixture if you prefer a thicker sauce.

Step 13: Strain the sauce into a bowl and transfer to a sauce jug for serving.

Tips & Variations

Bringing the beef to room temperature before cooking ensures even cooking and a tender roast.

If fresh herbs are unavailable, dried rosemary and thyme work well, just use half the amount.

Use a meat thermometer to avoid overcooking; temperature is key for perfect doneness.

For different doneness levels, adjust the internal temperature: 49°C for rare, 57°C for medium.

Complement the roast with creamy mashed potatoes and sautéed greens for a complete meal.

FAQs

Can I cook the prime rib without the bone?

Yes, boneless prime rib can be cooked the same way, but the bone helps retain moisture and adds flavor. Adjust cooking time slightly, as boneless roasts cook faster.

How do I know when the beef is done?

The most reliable way is using a meat thermometer. For medium rare, aim for an internal temperature of 51°C (123.8°F) before resting. The temperature will rise during resting for perfect doneness.