Chop celery, carrot onion, garlic, and jalapeno. In a skillet sautÚ in one teaspoon of cooking oil until seared and almost tender. Cut up chicken and add to the mixture. Simmer until chicken is cooked through but not very brown. Place mixture into a large pot. Add chicken broth, tomatoes with the juice, chili powder, and salt and pepper to taste.
Cut uncooked tortillas into long strips In a skillet put an inch of cooking oil in the bottom of the skillet. Fry the tortilla strips until they are crispy, this takes practice, and until you get the hang of it you may want to have some pre-fried, or baked tortillas on hand.
Five minutes before serving add grated cheese and the pealed and diced avocados to the soup. Let it simmer until the cheese melts. To serve ladle into large bowls that will have room for a garnish of extra cheese tomato, avocado, and of course a blob of sour cream.