Trim fat off prime rib, leaving some for insulation. Also, remove tendon on fat side.
Coat with black pepper, garlic powder, Montana Outlaw BBQ Beef Rub.
Let it rest for at least 2 hours, up to 8 hours.
Cook with kamado-style grill, fat side down for 2 hours.
Meanwhile, prepare baste: on low heat, melt 1 stick of salted butter and add smashed cloves of garlic, rosemary, thyme.
Flip prime rib on grill and baste, then cook until internal temperature reaches 135°.
Remove and rest for 10 minutes to a half hour.
Slice against the grain and serve immediately.