- In a large bowl, combine the ancho and Anaheim chilies, the tomatoes, onion and garlic. Working in batches, coarsely puree in a blender. Transfer to another bowl.
- In a Dutch oven over medium-high heat, warm the canola oil until almost smoking. Add the chili mixture and cook, stirring occasionally, for 15 minutes. Stir in the stock and water. Bring to a boil, reduce the heat to medium-low and simmer for 20 minutes. Stir in the chicken and chopped cilantro.
- Meanwhile, in a deep fryer, pour in vegetable oil and heat to 375F according to the manufacturer's instructions. Working in batches, fry the tortilla strips until crisp, about 2 minutes. Using a slotted spoon, transfer to paper towels to drain.
- Ladle the soup into warmed bowls. Garnish with the tortilla strips, cilantro leaves, cheese and avocado slices and serve immediately. Serves 6.