Cut the pork into large cubes (1 ½ to 2 inches). Heat a Dutch oven or large pot over medium heat and add the oil. Add the pork to the Dutch oven and generously season with salt and pepper.
Sear the pork on all sides. If would be best to sear them in two batches to avoid overcrowding the pot.
Once they are all seared, place all the pork carnitas back into the pot.
Roughly chop the onions, cut the onion into 4ths and peel the garlic cloves.
Add the onions, garlic cloves, and Mexican oregano.
Add the pineapple juice and milk, and add orange juice by squeezing the oranges then add the orange pieces into the dutch oven.
Bring the carnitas to a fast simmer, then turn down the heat to a slow simmer and add the chopped green chile. Cover and slow simmer for about 1 to 1 ½ hours.
Uncover the green chile pork carnitas and gently stir, add a bit more pineapple juice or water if they are too dry. Keep cooking the carnitas for another 30- 45 minutes uncovered. until the liquids start drying out.
Pour the carnitas into a 9 X 13 roasting pan. Preheat oven to broil and place pan into oven to brown the tops of the meat. This step is optional but I do like a little added browning.
Serve on a plate with a side of pico de gallo with feta cheese and avocado and a flour tortilla on the side. Or serve these carnitas wrapped in a warm flour or corn tortilla along with with pico de gallo and avocado.