Brush rib roast lightly with olive oil. Rub sea salt, black pepper, and garlic into the roast. Place fatty-side up on a rack set inside a shallow pan.
Roast in the preheated oven until browned, about 30 minutes. Reduce oven temperature to 325 degrees F (165 degrees C) and tent pan with aluminum foil. Continue cooking until an instant-read thermometer inserted into the center of the rib roast registers 140 degrees (60 degrees C), about 1 hour.
Let rib roast stand for 10 to 20 minutes before carving.