Step 1

Cut just into the fat pad on top of the meat at a diagonal and then turn the opposite direction and cut again to make a diamond pattern.

Step 2

Rub the salt and pepper all over the meat and place in the fridge for 12-24 hours.

Step 3

In a small bowl, whisk together the Dijon mustard, Worcestershire sauce, garlic, and rosemary.

Step 4

Rub the outside of the roast with the mustard paste.

Step 5

Set the Traeger to 250℉ and preheat, lid closed for 15 minutes using apple wood and hickory pellets.

Step 6

Put the prime rib directly on the grill grate, fat-side up. Roast for 3-1/2 to 4 hours, or until the internal temperature of the meat reaches 125-130℉ for rare, or for medium-rare, 135℉. Do not overcook.

Step 7

Remove to a cutting board and tent with foil for 20-30 minutes, slice and serve.