Perfect Prime Rib

This was a roast that I made for my birthday. First I brought the roast to room temperature and rubbed with pepper, and thyme and then slathered it with unsalted butter. I then covered it with onions and put it in the oven at 475F for fifteen minutes then lowered the temperature to 325F until I got an internal temperature of 135F. I remove the roast from the oven and let it rest for approximately 15-20 minutes covered in  tinfoil. It was delicious.