Sopa Azteca (Tortilla Soup)

• 1 large dried pasilla chile, stemmed and seeded
• One 15-ounce can diced tomatoes in juice, preferably fire-roasted
• 2 tablespoons vegetable or olive oil
• 1 medium white onion, sliced 1/4-inch thick
• 3 garlic cloves, peeled
• 2 quarts chicken broth
• 1 large epazote sprig (optional)
• 4 boneless, skinless chicken breast halves (about 1 1/4 pounds total), cut into 1/2-inch cubes
• 1 large ripe avocado, pitted, flesh scooped from the skin and cut into 1/4-inch cubes
• 1 1/2 cups (6 ounces) shredded Mexican melting cheese (like Chihuahua, quesadilla or asadero) or Monterey Jack, brick, or mild cheddar
• Generous 4 cups (about 6 ounces) roughly broken tortilla chips
• 1/2 cup Mexican crema, sour cream, or creme fraîche for garnish
• 1 large lime, cut into 6 wedges, for serving

Quickly toast the chile by turning it an inch or two above an open flame for a few seconds until the aroma fills the kitchen. (Lacking an open flame, toast it in a dry pan over medium heat, pressing it flat for a few seconds, then flipping it over and pressing it again.) Break the chile into pieces and put in a blender jar along with the tomatoes with their juice. (A food processor will work, though it won’t completely purée the chile.)

Heat the oil in a medium (4-quart) saucepan over medium-high. Add the onions and garlic; cook, stirring frequently, until golden, about 7 minutes. Scoop up the onions and garlic with a slotted spoon, pressing them against the side of the pan to leave behind as much oil as possible, and transfer to the blender. Process until smooth.

Return the pan to medium-high heat. When quite hot, add the purée and stir nearly constantly, until thickened to the consistency of tomato paste, about 6 minutes. Add the broth and epazote, if using. Reduce the heat to medium-low and simmer for 15 minutes. Taste and season with salt, usually about a generous teaspoon (depending on the saltiness of the broth).

Just before serving, add the chicken to the simmering broth. Divide the avocado, cheese, and tortilla chips between serving bowls. When the chicken is done, usually about 5 minutes, ladle the soup into the bowls. Garnish with the crema. the lime separately.