If the beef is completely dry, liberally apply a thin layer of yellow mustard (or binding agent of choice) to the meat before applying the rub.

Coat the outside of the mustard-coated meat generously with the prime rib dry rub.

Transfer the meat to a platter and place it inside the refrigerator for no less than one hour before cooking. Rubbing the meat in advance will allow the meat to take on the seasoning and form a crust.

Prepare the grill for a 3-Zone Split Fire. To make this set up, put one charcoal basket of charcoal on each side of the grill. Place a drip pan in the center of the two baskets to catch the drippings from the meat (the video above for a demonstration).

For high heat, light a charcoal chimney starter full of charcoal.

When the charcoal is covered in ash, pour it equally into the charcoal baskets on each side of the grill and put an aluminum drip pan in the middle of the two baskets.

Preheat the grill to 325-350 degrees F.

Set up the rotisserie according to the manufacturer’s instructions.

Center the roast on the rotisserie spit and secure it with the spit forks. Give the spit a few twirls in your hands to ensure even turning, and that is centered well before tightening the forks all the way.

Put the spit on the rotisserie, start the motor. Let the roast rotate a couple of times to ensure it turns evenly. Place the lid on and grill it over indirect heat for 30 minutes.

Meanwhile, prepare the garlic herb basting butter. Over medium-low heat, add the butter, olive oil, thyme, rosemary, garlic, and soy sauce in a small pot. Heat until the butter melts, and it becomes fragrant. Be careful not to get the butter too hot, or it will burn and scorch the garlic. Turn off the heat and set it aside until needed.

You can use a grilling/basting brush or make a herb brush to baste the meat. Remove the lid from the grill and baste the roast with the basting butter. (Rotate the meat if you are not using a rotisserie) Close the grill and continue to grill, basting every 30 minutes until the internal temperature is 130-135 degrees F for medium-rare when read with an Instant-Read Thermometer; about 1 ½ to 2 hours.

Transfer the roast from the spit to a carving board. Tent with foil and allow it to rest at least 20 minutes before carving.

Carve and serve warm.