Heat one tablespoon of oil in the stock pot. When the oil is hot, add the sliced onion and peeled garlic. Fry until light brown and add to a blender.
Drain the tomatoes and add to the blender. Blend until smooth.
Add another tablespoon of oil to the stock pot and add the tomato mixture. Stir until thick and darker, about five minutes. Then add the chicken stock.
Add the teaspoon of salt, cover, and simmer for thirty minutes over medium-low heat.
Place the unshucked corn into a microwave and set for 4 minutes. When done, remove from the microwave with an oven mitt. Slice the bottom, just above the stem, and, using a fork, pull the corn out of the husk. It should come out clean. Using a thin sharp knife, slice the corn kernels into a large mixing bowl.
Add water to a saucepan and bring to a boil. Add the chicken breast a boil until done. It should be 165 degrees or higher on a meat thermometer. Place on a cutting board, and using two forks, shred the chicken against the grain.
Heat 1/3 cup oil in a skillet to medium. When hot, add the prepared pasilla peppers and stir for 5 or 6 seconds. Remove and place on a plate with a paper towel to drain. Add the prepared tortillas.
Cook until light brown and crispy. Remove to a plate with a paper towel to drain.
When the soup has cooked for 30 minutes, add the corn and the chicken, and stir for two minutes.
ASSEMBLING THE SOUP: Place three tablespoons of melting cheese in a deep bowl. Add the soup, top with pasilla peppers, tortilla chips, and avocado, and serve with a slice of lime.