Pork butt is best for green chili stew IMO. I like to buy the boneless ones from Costco when making green chili. Their vacuum packed two to a pack, so about 15-17 lbs per package.
Campfire, roast some Poblanos or Anaheims on the embers, peel, chop, then throw in a pot with some onions, cubed butt, spices, water or stock, and let it go over the fire until the meat starts to fall apart, about 3-4 hours depending on the simmer. DANG! I wanna be a Boy Scout again!
You can do the same thing with brisket or chuck roast and red chilies, but you pay more for the meat. Or you can buy the already dried red chilis (I like Pasilla/Ancho dried chilies). Soak the chilies in some boiling water, remove, chop, throw back in the soak water, add the cubed beef, onions, spices, more water or stock if necessary, and simmer until it falls apart.
Man oh man I'm hungry now. They'll earn their Eatin' Merit badges, that's for sure!