- 4 ounces whole mild-to-medium-hot dried red New Mexican chiles (16-20 small to medium), stemmed and seeded
- 2 cups reduced-sodium chicken broth, divided
- 1 1/4 cups chopped onion
- 3 cloves garlic, minced
- 2 tablespoons sherry vinegar or cider vinegar
- 1 1/4 teaspoons dried oregano, preferably Mexican
- 1 teaspoon salt
- 2 1/4 pounds boneless, skinless chicken thighs, trimmed and cut into 1-inch cubes
- Preheat oven to 300°F. Coat a large baking dish or Dutch oven with cooking spray.
- Rinse chiles; spread out on a baking sheet. Toast in the oven until darkened and fragrant, 2 to 4 minutes per side. Let cool, then break each chile into several pieces.
- Puree half the toasted chiles with 1 cup broth in a blender until only tiny pieces of chile are visible. Pour into the prepared baking dish. Puree the remaining chiles with the remaining 1 cup broth, onion, garlic, vinegar, oregano and salt until smooth. Pour into the baking dish and stir together with the rest of the sauce. Add chicken; stir to coat.
- Bake until the chicken is tender and the sauce is thick, about 1 1/2 hours.