Prep The Pork Shoulder: Cut the pork into small strips, approximately 2 inches wide.
Make The Sauce: Place all the ingredients (orange juice, vinegar, onion, herbs, and spices) for the sauce in a blender and blend until they are very well mixed.
Add Sauce & Pork To Pot: Pour the sauce from the blender into the Instant Pot. Then place the strips of pork shoulder into the pot, ensuring that each piece is thoroughly covered with sauce.
60-Minute Cook Time: Close the Instant Pot, set the pressure release valve to 'Sealing', and set the pot to cook on 'Manual' or 'Pressure Cook', 'High Pressure' for 60 minutes.
30-Minute NPR: Once the cooking time has completed, allow for a 30-minute natural pressure release. When the 30-minute NPR has finished, release the remaining pressure and then open the pot.
Shred & Marinate Pork: Remove the meat from the pot and shred. Pour some of the liquid from the pot over the shredded pork and allow to marinate in the liquid until ready to serve.
Warm some corn tortillas.
Serve the shredded meat on the tortilla and top with Pickled Red Onion & Habanero Salsa.