Step 1Trim as much visible fat as possible from the pork butt. Cut the remaining meat into 1-inch cubes, reserving any bones.
Step 2Place the pig's feet, neck bones and pork bones from the pork butt in the bottom of a 6- to 8-quart stock pot and add the cubed meat on top. Add the onions, garlic, bay leaves and chile. Fill the pot with water. Bring to a boil and skim any scum that floats to the top. Reduce the heat to very low and cook 4 hours. Remove from the heat and refrigerate 8 hours or overnight.
Step 3The next day, using a slotted spoon, skim the congealed fat from the top of the stock. Remove the onions, bones and bay leaves and discard. Remove the pigs feet and separate the meat from the bones. Chop the meat (including the skin) coarsely and return to the pot.
Step 4Place over low heat and cook another 2 hours. Add the pozole corn and cook until the kernels open and the meat is falling apart, another 2 hours. If the soup becomes too dry, add more water. Season to taste with salt and plenty of pepper. Add the oregano. Stir and cook 30 more minutes to let the flavors meld.