How to Make It
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.
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.
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.