Ingredients

• Ingredients
  1. Four 6-inch corn tortillas
  2. 1 to 2 tablespoons vegetable oil
  3. 8 cups chicken stock or canned low-sodium broth
  4. 4 fresh or canned plum tomatoes, coarsely chopped, with their juices
  5. 1 medium all-purpose potato, peeled and cut into 1/3-inch dice
  6. 1 ancho chile—stemmed, seeded and cut into thin strips
  7. 1 medium onion, thinly sliced
  8. 2 garlic cloves, coarsely chopped
  9. 1/2 teaspoon marjoram
  10. Salt
  11. 1 small zucchini, cut into 1/2-inch dice
  12. 1 small yellow squash, cut into 1/2-inch dice
  13. 1 pound small skinless, boneless chicken breast halves, cut crosswise into 1/2-inch strips
  14. Cilantro sprigs, for garnish
  15. 1 lime, quartered, for garnish
  16. Sour cream, for garnish

Directions

1. Preheat the oven to 425°. Brush both sides of the tortillas with the vegetable oil, cut them into 1/2-inch-wide strips and spread them in a single layer on a large baking sheet. Bake for about 5 minutes, or until golden.
2. In a large nonreactive saucepan, combine the stock, tomatoes, potato, ancho, onion, garlic, marjoram and 1 teaspoon of salt; bring to a boil. Reduce the heat to moderate; simmer until the vegetables are almost tender, about 15 minutes. Add the zucchini and yellow squash; cook for 1 minute longer. Add the chicken and simmer until just cooked through, about 5 minutes. Season with salt.
3. Ladle the soup into warmed soup plates or bowl. Float a few tortilla strips on top of each serving and garnish each with several cilantro sprigs, a lime quarter and a dollop of sour cream. Serve the remaining tortilla strips on the side. Enjoy the soup right away, before the tortillas become soggy.