1Heat gas or charcoal grill. In large bowl, mix beef, green chiles and chipotle chiles. Shape into 8 patties, about 3/4 inch thick.
2In medium bowl, mash guacamole ingredients, using pastry blender or fork.
3Place patties on grill over medium heat. Cover grill; cook 13 to 15 minutes, turning once, until meat thermometer inserted in center of patties reads 160°F. Top each patty with cheese slice; cook just until cheese is melted. To toast buns, place cut sides down on grill during last 1 to 2 minutes of cook time.
4Layer buns with tomato slices, burgers and guacamole.