Ingredients

1. 3 cups fresh corn kernels (from 5 ears)
2. 5 tomatillos (3/4 pound), husked and finely chopped
3. 3 jalapeños, seeded and finely chopped
4. 2 cups apple cider vinegar
5. 1 large onion, finely chopped
6. 1 red bell pepper, finely chopped
7. 1/2 cup sugar
8. 1 teaspoon yellow mustard seeds
9. 1 teaspoon celery seeds
10. 1/2 teaspoon coriander seeds
11. Salt
12. 3 pounds skirt steak, cut into 1/4-inch dice and chilled
13. Freshly ground pepper
14. 3 ounces creamy blue cheese, such as Cabrales
15. 6 sourdough rolls, split and lightly toasted

Directions

1. In a large saucepan, combine the corn, tomatillos, jalapeños, vinegar, onion, bell pepper, sugar and the mustard, celery and coriander seeds. Bring to a boil; simmer over moderate heat until thickened, 40 minutes. Let cool and season with salt.
2. Light a grill. Working in small batches, put a handful of diced skirt steak in a food processor and pulse about 4 times, until very finely chopped. Transfer to a bowl and repeat with the remaining skirt steak. Pat the mixture into 6 burgers.
3. Season the burgers with salt and pepper and grill over a hot fire until medium rare, 3 minutes per side. About 1 minute before the burgers are done, place the blue cheese neatly on top of them. Set a burger on the bottom half of each roll, spoon some relish onto each, close the sandwiches and serve.

Make Ahead

The cooked and cooled tomatillo-corn relish can be refrigerated for up to 1 week.