Preheat the oven to 275° or your slow cooker to high.
Pat your pork shoulder dry then brush all over with mustard
Mix all of the dry rub ingredients together and sprinkle liberally on all sides of the shoulder.
Place the shoulder in a crock pot (or if cooking in the oven, place deep roasting pan with a heavy lid).
Next, pour all of the sauce ingredients into a bowl or blender and mix until combined. Pour the sauce over the shoulder.
Put the lid on, and cook for 3-4 hours or until fall apart tender.
Skim the fat off of the liquid in the pot, then take 2 forks and shred the meat, removing the bone if there is one.
Transfer the shredded pork to a lined baking sheet and spoon on some of the cooking liquid.
Set the broiler to high, and place the sheet pan on the second highest oven rack. Allow to broil until the meat us dark brown and crispy, about 6-8 minutes
Garnish with green onion and sesame seeds. Serve on buns, in tacos, or alongside rice or your favorite BBQ sides.