In a small bowl, mix together the garlic powder, onion powder, smoked paprika, salt, and black pepper.
Rub the mixture on the chunks of pork.
To cook the pork
Add the oil to the Instant Pot and turn to SAUTE. Once the oil is hot, add some of the pork pieces (do not overcrowd) and brown on all sides. Remove to plate and continue with the rest of the portions of pork.
Add half of the broth to the Instant Pot. With a wooden spoon, deglaze the pot by scraping up all of the stuck-on bits of food and seasoning.
Add the rest of the broth and the onion to the pot.
Return the pork to the Instant Pot. Cover, seal, and cook on HIGH (manual) pressure for 80 minutes.
Once the pressure has built and the cook time has elapsed, allow the pressure to release naturally for 15 minutes (do not open immediately or the meat may be tough).**
Vent to release any remaining pressure then carefully open the Instant Pot.
Using forks or tongs, shred the pork in the pot.***
Scoop out all the pork and onions that had cooked along with the meat and place it in a container until ready to serve.
Notes
*I prefer using a bone-in pork shoulder/butt roast for this recipe. You can use boneless if you'd like.**If after you've released the residual pressure and opened the lid, you find the meat is not fall apart tender, you can replace the lid and cook for a little longer at high pressure.***You can remove the pork to a bowl for this step, but I find it just as easy or easier to use tongs to pull apart/shred the meat right in the instant pot.