Prepare your grill for smoking with indirect heat at a target temperature of 250 degrees.

Trim the boneless pork loin if you wish, or score the fat cap in a diagonal pattern by cutting diamond shapes into the fat with your knife about 1/4" deep.

Coat the pork with a thin, even layer of yellow mustard on all sides.

Apply a liberal coating of your favorite barbecue seasoning or rub on all sides.

Once your grill is heated, place the pork loin on your grill grates, on the opposite side of the grill than your coals or heat source.

Smoke the pork loin for about 30 minutes per pound of meat, or until the internal temp of the pork is about 140-145 degrees.

Basting Instructions (optional) - If you wish to baste your meat, then heat your favorite barbecue sauce. Baste your pork when the internal temp of the meat is about 10 degrees from being done, or about 130-135 degrees. Brush on a good amount of sauce on the top of your pork loin, wait for a few minutes, flip the loin, and baste the other side. Repeat as desired.

Remove the smoked pork loin from the grill, and allow it to rest for a full 20-25 minutes before slicing.