1. Place pork, broth, onion, coriander, cumin, oregano, chilies if using, and bay leaves in a 5to 6 litre pan. Add enough water to just cover the meat. Cover the pan and bring to a boil; reduce heat and simmer until meat pulls apart easily with a fork (3 to 4 hours).
2. Lift our meat (reserve broth for other uses, if desired). Discard fat. Place pork in a large roasting pan and bake, uncovered, in a 450� oven until sizzling and browned (about 20 minutes). Pull off chunks of meat and shred with -20ºC orks, discarding fat.