Place the corned beef brisket into a pan, fat side down, for ease of cleanup.
Slather a thin coat of Dijon mustard on the top and sides of the brisket.
Apply Jeff's original rub (get the recipes here) generously all over the top and sides of the brisket and let it continue to sit until it get's a "wet" look. (about 10-15 minutes)
Flip the brisket over to fat cap up and repeat the mustard and rub on the fatty side of the brisket.
Let the brisket sit while you go get the smoker ready for cooking at 240°F using indirect heat.
Place the pan of brisket on the smoker grate and let it cook until it reaches about 160°F.
Cover the top of the pan with a piece of foil and let it continue cooking with just heat until the meat reaches a temperature of 195-200°F.
Use a skewer or toothpick to check for tenderness. It should have little to no resistance when inserted.
Let the meat rest with a piece of foil loosely tented over the top for approximately 30 minutes before slicing.