Coat the beef shank with yellow mustard and season with Dad's All Purpose rub and pepper.
Preheat the smoker to 250 degrees and set for indirect heat. Place the seasoned beef shank vertically on the grill and let it smoke for about 6 hours or until the internal temperature reaches between 160-170 degrees.
Wrap the smoked beef shank with aluminum foil, adding 1/2 can of beer inside the wrap. Increase the grill temperature to 275 degrees and place it back on the smoker.
Cook the beef shank until it is probe tender, approximately 3-4 hours.
Remove from the smoker, keep it wrapped and rest it for 30-45 minutes.