Allow the pork to sit at room temperature for 15 minutes before starting. Trim excess fat and cut roast into 4 pieces, removing any bones.
Add spices to a large bowl and whisk together. Add pork to the bowl and toss until well coated.
Turn Instant Pot to the Saute setting. Add olive oil and heat until hot. Add pork and brown on all sides, about 2 minutes per side. Remove pork and set aside.
Add the chicken broth and deglaze the bottom of the pot, making sure to scrape up all the browned bits with a wooden spoon. Add the apple cider vinegar and mix together.
Place the pork chunks back into the pot. Select Manual High Pressure setting for 60 minutes and set the valve to the Sealing position.
After cooking is complete, allow the pressure to naturally release for 15 minutes. Manually release any remaining pressure.
Remove cooked pork to a large platter or bowl, cover loosely with foil and allow to rest for 5-10 minutes. Shred meat with 2 forks.
Serve on toasted buns with desired topping (BBQ sauce, coleslaw).