Remove the prime rib from the refrigerator 4 hours before cooking.
OPTIONAL: Minutes before cooking, bone and tie the roast.
Cut 1/2" slits on the top of the roast and insert minced or sliced garlic.
Rub the outside of the roast with high quality olive oil.
Combine the rosemary, thyme, kosher salt, black pepper, onion powder and garlic powder and spread evenly over the roast.
Let rest while the oven pre-heats to 500 degree F (260 degree C).
Transfer the roast to a roasting pan, bone side down.
Insert the thermometer into the center of the roast and place in the oven (2nd rack from the bottom).
Calculate your initial cooking time by allowing 5 minutes per pound of meat (a 9 lb roast would cook for 45 minutes while a 6 lb roast would cook for 30).
This will provide a nice crunch on the exterior. The seasoning rub will get charred but that's what creates the deeply savory crust.
After your calculated cooking time is up, turn the oven off but DON'T OPEN THE OVEN DOOR.
After 2 hours the center of your roast will be 135 degrees F, which is medium-rare.
If you prefer medium just keep it in the oven until it reaches 150 degrees F.
Remove from the oven and let rest for 10 minutes.