Season your chunked meat with a desired amount of kosher salt and black pepper.
Add oil to your Instant Pot and press the saute button.
When the oil is hot add the pork in batches and brown. Add your brown meat to a plate and add more oil between batches if necessary.
After all your pork is browned add in the onion and saute for about 5 minutes just to help soften the onions. Turn the Instant Pot off.
Let the pork and onions hang out while you make the puree for your soup. The Instant Pot will be off so the onions should be ok and not brown much.
In the jar of a blender add tomatillos, green chilies with liquid, cilantro, garlic cloves, jalapeños, oregano, cumin and the chicken stock.
Puree on high until the mixture is smooth.
Add the pork back to the Instant Pot and pour the soup puree over the pork. Stir to combine.
Secure the lid, make sure the nozzle is placed to "seal" and cook on the high manual setting for 50 minutes. The Instant Pot will take about 10 minutes to reach pressure.
When the cooking time is over manually release the pressure and remove the lid when unlocked.
Stir to combine and remove about 1/2 of the meat.
Shred and add back ot the pot and stir.
Stir in the white beans.
If the soup is thinner than you like you can put the Instant Pot on saute and cook down until your desired consistency is met.
To serve, top with a desired amount of fresh cilantro, corn chips and Cotija cheese.