Cut the pork into 4-5 inch chunks. If using bone-in, cut around the bone. If you'd like, trim the fat around the meat.
Add the pork (and the bone) to the Instant Pot.
Sprinkle the pork with 3 tsp of sea salt, making sure to cover all sides.
Add the onion to the pork.
Pour in pineapple juice, apple cider vinegar, and dijon mustard over the pork and onions.
Close the lid and set the Instant Pot to Manual on HIGH for 60 minutes.
Once the Instant Pot beeps to a finish, wait 10 minutes for the pressure to naturally release, then release the rest of the pressure manually.
Open the lid and transfer the pork and onions to a large bowl, along with 1 cup of the liquid. Discard the rest of the liquid.
Remove the fat if you prefer, then use 2 forks to shred the pork into bite-sized pieces.
In a separate bowl, whisk together 2 tsp sea salt and the rest of the spices together.
Sprinkle the spices over the pork and onions and toss together.
Serve warm, or freeze into individual portions.