Remove the prime rib from the refrigerator and let it sit at room temperature for about 1 hour.

Preheat your oven to 450°F (232°C).

Pat the prime rib dry with paper towels. This will help achieve a nice crust.

In a small bowl, mix together the kosher salt, cracked black pepper, and cracked green peppercorns.

Rub the roast all over with the olive oil, then generously season with the salt and pepper mixture.

Slice the top off the head of garlic to expose the cloves. Drizzle with a little olive oil and wrap in aluminum foil. Place the wrapped garlic in the oven alongside the prime rib.

Place the seasoned prime rib on a roasting rack in a roasting pan. Roast in the preheated oven for 20 minutes.

After 20 minutes, reduce the oven temperature to 325°F (163°C) and continue roasting for about 1.5 to 2 hours, or until the internal temperature reaches your desired doneness (medium-rare: 135°F/57°C, medium: 145°F/63°C).

While the roast is cooking, combine the softened butter, roasted garlic (squeezed out of the skins), chopped rosemary, thyme, parsley, lemon zest, sea salt, and freshly ground black pepper in a bowl. Mix well until all ingredients are thoroughly combined.

Once the prime rib has reached the desired temperature, remove it from the oven and tent it loosely with aluminum foil. Allow it to rest for at least 20 minutes to let the juices redistribute.

Slice the prime rib to your desired thickness and serve with a generous dollop of herb-infused confit butter on top. Enjoy!