Preheat the oven to 300 degrees. Whisk together the spice rub ingredients to thoroughly combine them.
Slice the oranges and onions, peel the garlic. Place in the bottom of a large roasting pan. This will become the "rack" for the pork roast to rest on top of. If your roasting pan has a rack in it, set it aside, the oranges and onions taste much better!
Score the fat on the top of the pork in a checkerboard pattern and season liberally with 1/4 C of the spice rub. Place the roast onto the oranges and onions.
Whisk together the apple cider vinegar, brown sugar and water until the sugar dissolves. Pour into the bottom of the roasting pan and cover tightly.
Roast in 300 degree oven for at least 3 hours until the roast is fork tender. Using two forks, pull the pork into bite sized pieces. If you're making this up ahead of time, cool the pork in the pan juices.
This recipe freezes really well, and can be made up ahead of time. When you are heating it, just do so on the stovetop in the pan juices that the pork cooled and stored in.
The pork makes great sandwiches with some coleslaw and pickles, but also is amazing in tacos or on pizza.