Cut the pork shoulder (pork butt) into chunks, about 1-2 inches. Season all over with cumin, salt and pepper. Set aside.
Peel the outer skins off the tomatillos, onion and garlic. Cut the stems off the peppers and slice in half lengthwise. Cut the onion in half. (See Note 1)
In the Dutch oven or large stock pot bring 6 cups of water to a boil. Add the tomatillos, chiles and onion. Cook for 8 minutes. (See Note 2)
Carefully remove with a slotted spoon and place all the peppers, tomatillos, onion, garlic and cilantro in a food processor, blender or Vitamix, and process until smooth. Reserve 1 cup, set aside.
In a large skillet or Dutch oven over medium high heat add the oil. When oil shimmers, add the pork and, working in batches so they brown and not steam, cook on all sides.
Add all the cooked pork back to the Dutch oven and pour the pureed tomatillo green pepper sauce over and mix together completely to incorporate. Bring to a quick boil, close the lid and cook on low for 3 hours or until fork tender, stirring occasionally.
After 3 hours, stir in remaining 1 cup cilantro infused chile verde puree (See Note 3). Serve hot with warmed tortillas or biscuits to sop up the amazing chile verde gravy.
Instant Pot Method
This could easily be cooked in the Instant Pot, too. Just brown the pork as directed on the Sauté setting (in batches to brown, NOT steam) and pour the vegetable chile puree on top. Close the lid and press the Manual setting on High for about 20 minutes. Allow for a Natural release and you're ready to eat. (See Note 3)
Video
Notes
Pork shoulder is also known as pork butt. When boneless, it's often sold wrapped in cloth netting.
If you prefer, you can grill or place the tomatillos, chiles and onion under the broiler for a charred flavor instead of boiling.
Optional ingredients to add to this to make it go further are fork tender, cubed and boiled red potatoes or cooked beans. Add after the 3 hour mark, stir in cooked potatoes or beans with remaining cup of chile verde puree, cover and heat to warm through.