A fantastic chile verde recipe.
Cut pork into 1/2-inch cubes; season cubes with salt and pepper.
In a large, heavy pan with lid, brown the cubes well in oil and melted butter. If your pork is already cooked - just add it here and skip to step 3
Add the onion and garlic and sauté for about 5 minutes, then drain the fat from the pan.
Add the remaining ingredients, cover, and simmer for at least 90 minutes, stirring frequently; add more water (or broth or beer) during cooking if necessary to achieve desired sauce texture.