Remove the prime rib from the refrigerator and let it sit at room temperature for 2-3 hours before cooking.
Preheat the oven to 450°F (232°C). While the oven is preheating, mix the softened butter, minced garlic, chopped rosemary, and chopped thyme in a bowl to create the garlic herb butter.
Pat the prime rib dry with paper towels and season generously with kosher salt and freshly cracked black pepper, guaranteeing even coverage on all sides.
Rub the garlic herb butter all over the roast, making sure to coat it thoroughly.
Place the prime rib bone-side down on a roasting rack set in a roasting pan. Insert a meat thermometer into the thickest part of the meat, avoiding the bone.
Roast the prime rib in the preheated oven for 20 minutes at 450°F, then reduce the oven temperature to 325°F (163°C) and continue cooking.
For medium-rare, cook until the internal temperature reaches about 120°F (49°C). The general cooking time is approximately 12 minutes per pound. Monitor the temperature carefully with the meat thermometer.
Once the desired temperature is achieved, remove the prime rib from the oven and let it rest for 20-30 minutes before slicing. This resting period allows the juices to redistribute, guaranteeing a juicy roast.