Step 1

Build a hot fire or preheat a gas grill to high.

Step 2

Mix turkey with cilantro, scallion, chili powder, cumin, salt and pepper in a large bowl. Shape into 4 patties, 1/2 inch thick. Refrigerate until ready to grill.

Step 3

Grill chiles until the skins are blackened and blistered, 4 to 5 minutes per side. Transfer to a clean cutting board and let cool slightly. Scrape off the skin with a paring knife, slice lengthwise and discard seeds and stems.

Step 4

Oil the grill rack. Grill the burgers until an instant-read thermometer registers 165 degrees F, 3 to 5 minutes per side. Top with cheese and grill until it melts, about 1 minute more. Transfer the burgers to a platter. Quickly warm tortillas on the grill. Serve the burgers in tortilla halves with a chile and sour cream, topped with lettuce and/or tomato, if desired.