Mix all spices and salt, rub all over pork butt, wrap tightly and refrigerate overnight.
Preheat oven to 300°F.
Place apple cider and onions in Dutch oven and bring to boil.
Place pork butt into Dutch oven, close tightly and place in oven.
Braise until pork is for tender, about 3-3 ½ hours.
Turn oven to 425°F and roast pork butt uncovered for an additional 15 minutes.
Remove from oven and let rest in liquid 15 minutes before shredding with fork.