1. 6 tablespoons cooking oil
2. 8 (6 inch) corn tortillas, halved and cut crosswise into 1/4-inch strips
3. 1 onion, chopped
4. 4 large cloves garlic, smashed
5. 1 tablespoon paprika
6. 2 teaspoons ground cumin
7. 1 teaspoon ground coriander
8. 1 teaspoon chili powder
9. 1/4 teaspoon cayenne
10. 1 1/2 quarts canned low-sodium chicken broth or homemade stock
11. 3 cups canned crushed tomatoes in thick puree
12. 2 bay leaves
13. 2 1/2 teaspoons salt
14. 1/4 cup lightly-packed cilantro leaves
15. 3 tablespoons chopped cilantro (optional)
16. 1 3/4 pounds boneless, skinless chicken breasts, cut into 3/4-inch pieces
17. 1 avocado, cut into 1/2-inch dice
18. 1/4 pound Cheddar, grated
19. Lime wedges, for serving
1. In a large heavy pot, heat the oil over moderately high heat. Add half the tortilla strips and cook, stirring, until pale golden, about 1 minute. Remove with a slotted spoon and drain on paper towels. Repeat with the remaining tortilla strips.
2. Reduce the heat to moderately low. Add the onion, garlic, and spices; cook, stirring, for 5 minutes. Add the broth, tomatoes, bay leaves, salt, cilantro leaves, if using, and one-third of the tortilla strips. Bring to a simmer. Cook, uncovered, for 30 minutes; remove the bay leaves.
3. In a blender, puree the soup in batches; pour it back into the pot. Add the chicken, bring the soup back to a simmer, and cook until just done, about 1 minute. Stir in the avocado.
4. To serve, put the remaining tortilla strips in bowls, top with the cheese, and pour in the soup. Sprinkle with the chopped cilantro, if using, and serve with the lime wedges.
Yield: 4 servings