Step 1

Wash and dry prime rib, then set it onto a pan. If the roast has a thick fat cap, trim some of the fat from the top of the roast.

Step 2

Mix kosher salt, freshly ground black pepper, Montreal steak seasoning, and cayenne pepper in a small bowl.

Step 3

Rub the seasoning into the prime rib. Go a little lighter on the ends, to keep them from being overly salty. Place on a rack over a tray and refrigerate overnight, uncovered.

Step 4

Prepare Herbed Butter: Add softened butter, herbs, and garlic cloves to a food processor (paid link). Blend until a paste is formed.

Step 5

Using a spatula, transfer the herb mixture into a small Ziploc sandwich bag and roll it into a log. Refrigerate the herbed butter until needed.

Step 6

Six hours before you plan on eating the prime rib, pull it out of the fridge along with the butter. Give it 2 hours to come to room temperature.

Step 7

After the prime rib has rested for 1 hour and 45 minutes, set your Traeger or electric smoker to 225 degrees F. Select Super Smoke and preheat 15 minutes. Spread half of the herbed butter over the prime rib, then place prime rib on the grill. Insert the probe or a meat thermometer into the thickest part, and set the probe temperature to 120℉.

Step 8

Begin checking the internal temperature after 3 hours. When the roast reaches 120℉, pull it off the grill and allow it to rest for 15 minutes. Meanwhile, kick up the Traeger's temperature to 450°F.

Step 9

Right before putting the prime rib back on the grill, brush the remaining herbed butter all over it. Re-insert the probe into the thickest part, and set the probe temperature to 130°F or 135°F for medium-rare to medium. It should take approximately 15-20 minutes to get to that temperature.

Step 10

When the smoked prime rib is ready, remove from the grill and wrap in foil for 15 minutes. If it's going to be a while before you serve it, wrap the foil-wrapped roast in a clean towel and place in a small cooler (without ice) until ready to serve.