Cut the pork shoulder 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.
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. Serve hot with warmed tortillas or biscuits to sop up the amazing chile verde gravy. (See Note 2)