1Place beans in food processor or blender. Cover and process until slightly mashed. In medium bowl, mix beans, chiles, onions, bread crumbs and egg. Shape into 5 patties, each about 1/2 inch thick. Coat each patty with cornmeal.
2In 10-inch skillet, heat oil over medium heat. Cook patties in oil about 10 minutes, turning at least once, until crisp and thoroughly cooked on both sides.
3Top patties with cheese. Cover and cook 1 minute or until cheese just begins to melt.
4Top bottom halves of buns with lettuce, patties, guacamole and salsa. Cover with tops of buns.