Preheat your oven to 275 F (135 C). 

Cut the pork into roughly 4-inch cubes. If you bought a shoulder with the bone in it, carefully cut off the large hunks of meat around the bone as best you can and add all the cubes, plus the piece with the bone in it, to an oven-safe pot or baking dish. 

Add the chicken stock to the vessel with the pork in it, and then add the spices and bay leaf. Stir the spices around with tongs or your hands, moving the pieces of meat to try to get things spread out some. Slice an orange in half, squeeze most of the juice out on top of the pork, and then add the orange halves to the pork. Nestle the onion quarters and garlic in as well. Cover the pot or pan tightly with foil and place it in the oven.

Bake for 3 hours. 

After 3 hours, turn off the oven and remove the pot or dish. Allow everything to cool for 10 or 15 minutes, and then, using a strainer, remove all the meat chunks to a bowl and strain off all the liquid into another pot or bowl. Discard the bay leaves, orange halves, onion, garlic, and any large spices. Do not discard the reserved broth/liquid. 

Using two forks or your clean fingers if the temperature isn't too hot, pull the pork into small bite-sized pieces and move the pork to a container that can be stored and sealed in the fridge. Add a bit of the reserved liquid and pour it directly into the container with the pork. Reserve the rest of the liquid in its own container in the fridge. 

When it's time to sandwich or turn into tacos, remove the amount of pork that you plan to eat and add it to a foil-lined sheet pan. Broil the meat in the oven for 6 minutes, and then, using tongs, toss the meat around to expose a second side and broil for an additional 6 minutes or until all of the edges of the pork start to crisp up. After the meat is broiled, splash a couple of spoons of the reserved liquid over the meat and toss to ensure that each piece of meat is coated in a bit of the reserved fatty broth. 

Serve and enjoy.