To roast poblano chilies, place on hot grill or directly over burner on a gas stove. Cook until surface of chile is charred, turn and continue on all sides, about 8 to 10 minutes. Immediately place peppers in a resealable plastic bag; close and let rest at least 5 minutes. Peel skin from peppers and remove seeds. Chop peppers. Peppers can be roasted ahead of time and refrigerated.