Pre heat the oven at 300 F.
In a dutch oven or cast iron pot, heat the olive oil at a medium heat, color the pork on all sides, then add the onions and sweet green chiles, season well with salt and pepper. Cook until the onions and green chiles are soft. Deglace the pot with stock (1.5 cups) and scrap all the flavors that are stock to the bottom of the pot.
Cover and put in the oven, let it cook for 1 hour and 30 minutes, you can verify at 1 hour and rectify the seasoning and add some stock if necessary.
When done, it will be tender and juicy, let it rest for 10 minutes the cut in slices and served with rice and black beans, put a spoonful of the onions and green chiles then place the sliced pork then spoon over the sauce! Enjoy!