¼ cup thinly sliced red onion
1 pound ground bison or lean (90% or leaner) ground beef
2 4-ounce cans diced green chiles, drained, divided
½ cup shredded pepper Jack cheese, divided
¼ teaspoon salt
¼ teaspoon freshly ground pepper
4 whole-wheat hamburger buns, toasted
1 cup very thinly sliced iceberg or romaine lettuce
Preheat grill to medium-high.
Place onion in a small bowl and cover with cold water.
Place bison (or beef), 1 can drained chiles, ¼ cup cheese, salt and pepper in a medium bowl. Gently combine without overmixing. Form into 4 patties, about ¾ inch thick.
Oil the grill rack. Grill the burgers, turning once, until an instant-read thermometer inserted in the center registers 155°F (165°F for beef), 4 to 5 minutes per side. Top each burger with an equal portion of the remaining green chiles and sprinkle with the remaining ¼ cup cheese. Cook until the cheese is melted, about 1 minute more.
Drain the onion. Assemble the burgers on toasted buns with onion and shredded lettuce.