Green Chile Sauce

11⁄2      pounds Anaheim or green New Mexican chiles

1           small onion (approximately 31⁄4 ounces), quartered

1           large clove garlic

1           jalapeño pepper (approximately 1⁄2 ounce), halved and seeded

1           tablespoon unsalted butter

1           tablespoon unbleached, all-purpose flour

11⁄2      cups chicken stock

3⁄4        teaspoon kosher salt

Preheat oven to 450°F. Arrange chiles on a baking sheet and roast until very dark and skin is coming away from the chile, about 30 minutes. Put chiles in a mixing bowl and cover with plastic wrap in order for the skins to loosen, about 15 minutes.

Peel the cooled chiles, discarding all skin, seeds, and stems. Melt the butter in a 31⁄2-quart saucepan over medium heat. Add the onion, garlic and jalapeños, sauté for about 4 to 5 minutes until soft. Stir in chiles and cook for another minute. Add flour and stir and cook for 2 minutes. Add stock and bring to a boil. Add salt and reduce to a simmer for about 25 minutes. Insert the blender into the saucepan, making sure the protective guard is submerged. Blend on Low using an up-and-down  motion until ingredients are well combined, about 40 to 60 seconds, until the sauce reaches desired consistency.