Roast your tomatoes and onion to get a little char on them. On a grill or open flame is preferred, but you can also roast them for 15 minutes in a 450 degree oven.
4 Medium Tomatoes, 1/4 Onion
In a small sauce pan, cook the whole garlic cloves over medium high heat. Simply heat them in the pan, without any oil, until they develop a little char. Do not burn the entire cloves.
2 Cloves Garlic
While the vegetables are roasting, add the chicken breast to a large pot along with the 5 cups of broth and the ancho chili. If your broth is unsalted, add about 1 tsp of salt.
3/4 Lb Chicken Breast, 5 C Chicken Broth, 1 Large Ancho Chili, Salt to Taste
Heat to boiling and simmer for about 15 minutes, covered, until the chicken is cooked through. Note: if you are using a whole chili, keep it whole for later.
Once the vegetables are roasted, blend the onion, tomatoes and garlic (and ancho chili if using a whole one). Make sure to remove any stems and inedible ends before blending.
Remove the chicken from the broth and add the blended vegetables to the broth. Continue to simmer the broth while you shred (or chop) the chicken. Keep the chicken to the side.
While the soup simmers, fry the tortilla strips. Heat the 1/2 cup oil in the same small pan you cooked the garlic in. Cut the 4 tortillas in half. Cutting perpendicular to your first cut, make 1/2 inch strips out of the tortillas. Fry the strips in the oil for 2-3 minutes until browned and crispy.
4 Corn Tortillas
Place the fried tortilla strips on a draining grate, or some paper towel, to cool. Sprinkle with salt while they are still piping hot.
Quarter the lime and slice the avocado.
1-2 Limes, 1 Avocado
Season the soup with salt to taste.
To serve, add a small handful of shredded chicken to a soup bowl and pour the broth over the top. Sprinkle with a few of the tortilla strips. Serve the soup with the lime, avocado, cilantro, cheese, extra tortilla strips (and optional sour cream) on the side, so everyone can pick their own toppings.
1/2 C Grated Monterrey Jack or Queso Fresco, 1 Bunch Cilantro, 1/4 C Sour Cream or Crema