Heat chopped sweet onion in a pan until tender and set aside to cool
Shred monteray jack cheese & drain green chiles
Add cheese, chiles, onion and spices to ground beef and mix gentlly
Form ground beef mixture into 4 patties
Lighlty brush burgers with olive oil
Grill burgers over medium high heat for 8-10 minutes turning once
Lightly toast buns if desired (roughly 1 minute)
Assemble burgers with mayonnaise on bottom, followed by a slice of tomato, the burger and top with guacamole