Remove the prime rib from the refrigerator and let it sit at room temperature for at least 1 hour.
Preheat the oven to 250°F (120°C). Pat the roast dry with paper towels, then rub it all over with olive oil, salt, and black pepper.
Place the roast on a rack in a roasting pan, bone side down if using a bone-in cut. Roast until the internal temperature reaches 120°F (medium-rare), about 3 hours.
Remove the roast from the oven and let it rest for 30 minutes while you prepare the garlic butter.
In a large skillet, melt butter over medium-high heat. Stir in minced garlic, rosemary, and thyme. Sear the roast on all sides for 1-2 minutes per side until a deep crust forms.
Transfer the roast to a cutting board, let it rest for 5 minutes, then slice thinly against the grain.
Serve warm with your favorite sides, such as mashed potatoes or roasted vegetables.