To make fat-free tortilla strips in the oven, slice corn tortillas into 1/4″ strips and put in a single layer on a baking sheet. Bake at 300 degrees F for about 15 minutes, shaking every 5 minutes, until dry and crispy.
To make this recipe with fresh chicken, poach two boneless, skinless chicken breast halves in the broth mixture for 10 minutes before adding vegetables. Remove and let cool, then shred. Recombine in the pot with the vegetables and continue as directed.
To make vegetarian tortilla soup, substitute a cup or two of cooked black or pinto beans for the chicken and vegetable stock for chicken stock.
Other vegetables you might like in this are green beans, cabbage, and corn.