Trim off excess fat from pork roast. Cut into cubes, roughly 2 inches. Transfer to a large bowl
Combine spices – salt, oregano, cumin, pepper, chile powder, and paprika – in in a small bowl. Rub pork with spice mixture. Coat the seasoned pork with olive oil. Add chopped onions and minced garlic and combine. Transfer to the pressure cooker pot.
Pour in orange juice until pork is covered, or mostly covered. Add more orange juice if needed. Let the pork marinade for at least 20 minutes; longer if desired.
Place lid on pressure cooker and cook for an hour and 10 minutes. Let pressure come down naturally.
Remove pork and shred. If desired, add pork back to pressure cooker pot and, if you're using a cooker with an air fryer, cook for about 5 minutes to get those brown tips on the edges of the meat.
