- 1 tablespoon extra-virgin olive oil
- 1 medium white onion, halved and sliced
- 2 cloves garlic, peeled
- 2 tablespoons ground ancho chile (see Ingredient notes)
- 2 tablespoons masa harina (see Ingredient notes)
- 1/4 teaspoon salt
- 4 cups reduced-sodium chicken broth, divided
- 8 ounces shiitake mushrooms, stemmed and sliced 1/2 inch thick
- 1 medium zucchini, cut into 1/4-inch cubes
- 1 sprig fresh flat-leaf parsley
- 2 boneless, skinless chicken breast halves, cut crosswise into 1/2-inch-thick slices
- Lime wedges for garnish
- Heat oil in a large saucepan over medium heat. Add onion and garlic and cook, stirring regularly, until golden, 5 to 7 minutes. Transfer the onion and garlic to a food processor or blender. Add ground chile, masa harina, salt and 1 1/2 cups broth; process until smooth.
- Return the puree to the saucepan. Bring to a boil over medium-high heat, whisking constantly, until slightly thickened, about 2 minutes. Add the remaining 2 1/2 cups broth, mushrooms, zucchini and parsley and return to a boil. Reduce heat to medium-low and simmer for 10 minutes. Stir in chicken and continue to simmer until cooked through, 6 to 8 minutes more. Remove parsley and ladle into soup bowls. Serve with a wedge of lime.