2) Place the cumin seed, fennel seed and coriander seed in a food grinder and grind fine. Transfer to a small mixing bowl and stir in the chili powder, onion powder and paprika.
3) Remove the shoulder from the brine and pat dry. Sift the rub evenly over the shoulder and then pat onto the meat making sure as much of the rub as possible adheres. More rub will stick to the meat if you are wearing latex gloves during the application.
4) Preheat the smoker to 100C. Place the shoulder in the smoker and cook for 10 to 12 hours, maintaining a temperature of 100C. Begin checking the meat to see if it is cooked after 10 hours of cooking time, using a fork. The meat is done when it falls apart easily when pulled with a fork.
5) Once done, remove the shoulder from the smoker and set aside to rest for at least 1 hour. Pull the meat apart with 2 forks and serve as sandwich, with coleslaw and dressing as desired.