Poach, not boil the chicken with carrot, onion and celery till done. Cool and cut up.
Combine tomatoes, soups, chili powder, tobasco sauce and reserved chicken broth in small bowl.
In 9x13 dish, layer in order: tortilla pieces, chicken, soup mixture, green onions, cheese. (I usually end up with three layers). Bake @ 350 degrees for 45 minutes. Let cool a few minutes before serving to let the cheese set up.
NOTE: Adjust heat for your particular taste by either adding more green chili's or using tomatoes without chili's. To save time you could also use a rotisserie chicken from your local deli.