1, 5-pound (2 kg) Prime Rib Roast bone out
1/4 cup Dijon mustard
1 tablespoon grainy mustard
1 tablespoon Worcestershire sauce
3 cloves garlic, minced
1 tablespoon coarsely ground black pepper
1 tablespoon kosher salt
1 tablespoon paprika
1 teaspoon dried thyme
2 teaspoons dried oregano
1 1/2 teaspoons dried rosemary
1 teaspoon ground coriander
1 teaspoon ground cumin
1 teaspoon chipotle chilli powder
Pat the meat dry with paper towels.
Mix the mustards, Worcestershire sauce, and garlic in a small bowl, and brush generously all over the meat. Combine all the dried herbs and spices in a small bowl and sprinkle generously over the mustard. Allow to sit at room temperature while you prepare the Keg.
Set the Electric Smoker to to 350°F (150°C), Place the prime rib on the smoker without a drip pan and let smoke for 4 hours. During this time, the temperature of the Keg should gradually fall to about 250°F (121°C). Test the internal temperature of the meat with a meat thermometer: it should reach 135°F (57°C) before resting and serving.