In a small bowl, combine the brown sugar, salt, paprika, cumin, and black pepper. Rub onto the pork shoulder. Set aside.
In the bottom of a slow cooker, add a layer of onions, chicken broth, and balsamic vinegar. Place the seasoned pork shoulder on top. Cover and cook on low for about 7 hours until very tender. Remove the meat. Reserve the liquid and let it cool.
When cool, use a fork or your hands to pull the meat into shreds. Remove any excess fat or grizzle.
Using a spoon, skim off any excess fat from the liquid in the slow cooker, Strain the liquid through a fine mesh sieve, reserving the liquid. Reserve one half cup of this liquid*. Return the rest to the crock pot with the shredded pork.
Add one cup of the BBQ sauce to the slow cooker. Mix to combine with the pulled pork. Cook for 30 minutes on low.
In the meantime prepare your red cabbage slaw. In a large bowl, combine the cabbage, onion, carrots, and kale.
In a separate bowl, whisk together the mayonnaise, lemon juice, grainy mustard, and honey. Add salt and pepper to taste. Add the dressing to the veggies until desired creaminess is achieved.
Once everything is ready serve the pulled board on slider buns, topped with purple cabbage coleslaw, and additional BBQ sauce if desired.
Notes
*This reserved liquid can be added to your cooked pulled pork for added moisture if desired.