For those folks who never tried them, here's how to roast: Get the grill hot, burners on high. Lay the Hatch Chilies on the grate, close the lid. Let them go a few minutes, you'll hear them cooking. Open lid , and turn them over. The skin should be turned black. When all blackened, put them in a bowl, and cover. Let them steam in their heat for at least a half hour. Now comes the work. Cut off the stem end, slice open, clean out the seeds. Store in a container for use in the fridge, or put in freezer bag for future.
I suggest trying mild first, as the flavor is fantastic. They are available in different heat ranges. Some will burn you good. I use them with eggs in the morning. Great on cheeseburgers. Pork stew with tomatillos. Lots of recipes on the web.