Make soup
Soak ancho peppers - Heat 2 cups water to near boiling and soak the ancho peppers for approximately 20 minutes. When peppers are soft, blend to puree.
In a medium stock pot, heat canola oil over medium heat. Add onions and garlic. Saute for about 5 minutes to soften.
Add chicken stock, diced tomatoes and ancho puree. Bring to a simmer, not a boil. Turn down the heat if necessary. Cook for 20 minutes.
Add shredded chicken, stir and simmer an additional 10 minutes.
Garnish tortilla soup with sliced avocado, tortilla strips, a squeeze of lime juice and cilantro.
Fry tortilla strips
While soup is simmering, fry tortillas - heat 1 quart of oil in a deep pot, leaving at least 3 inches of space from the top of the pot.
While oil is heating, cut tortillas in half and stack on top of each other. Cut into thin strips.
When oil has reached 350- 360 degrees, carefully place tortilla strips into oil. Fry until golden brown and crispy (about 3- 4 mins).
Remove from oil and lay on paper towels to drain. Sprinkle with salt.