Let the prime rib sit at room temperature for 1–2 hours before cooking to ensure even roasting.
Preheat the oven to 500°F (260°C).
Place the roast on a wire rack set inside a roasting pan. Pat it dry with paper towels, then season all sides generously with salt and pepper.
4 pounds boneless prime rib roast, 2 tablespoons salt, ½ teaspoon freshly ground black pepper
In a small bowl, combine the softened butter, rosemary, thyme, and garlic until well mixed. Spread the herb butter evenly over the top of the roast.
8 tablespoons unsalted butter, 2 tablespoons fresh rosemary, 2 tablespoons fresh thyme, 2 tablespoons minced garlic
Roast in the preheated oven for 15 minutes to sear and develop a golden crust.
Reduce the oven temperature to 325°F (165°C) and continue roasting for about 2 hours, or until the internal temperature reaches 120-125°F for rare and 130-135°F for medium-rare.
Begin checking the temperature every 30 minutes to prevent overcooking.
Remove from the oven, tent loosely with foil, and let rest for 20–30 minutes before slicing and serving.