Preheat Smoker to 225 degrees using a fruit wood (we like apple).
Coat the pork tenderloin with a layer of Dijon mustard (just to coat and allow the dry rub to adhere).
Sprinkle the dry rub liberally around the entire pork tenderloin.
Place tenderloin on the smoker for about an hour or until the internal temperature is 145 degrees Fahrenheit for medium rare, and then remove from heat. Like it more well done? Go for 160 degrees.
Let rest for 10 minutes and then slice thin for sandwiches.