To poach chicken; place chicken breast in saucepan, cover with 2 cups chicken broth, and place over medium heat until just boiling. Turn heat down to simmer and simmer for 10 minutes. Remove and place on cutting board to cool. Slice or shred into bite-sized pieces. Reserve poaching liquid.
Meanwhile, in large soup pot, heat olive oil. Add onion, garlic, cumin, and chili powder. Saute until onions are soft (add 1-2 tablespoons water if necessary).
Add the poaching liquid plus the remaining 3 cups of broth, corn, tomatoes, and beans. Bring to a boil, then reduce to a simmer for 5 minutes.
Meanwhile, stack tortillas together and slice in ¼" thin strips. Place in a single layer on a baking sheet. Lightly coat with cooling spray. Season lightly with salt. Bake for 8-10 minutes or until crisp. Set aside.
Add cut-up chicken, zucchini, and cilantro to soup and simmer for 2 minutes. Adjust seasonings if needed.
To serve, ladle soup into serving bowls and top with tortilla strips and shredded cheese.
Recipe by Little Miss Momma at https://www.littlemissmomma.com/2015/10/wellness-kitchen-best-chicken-tortilla-soup-recipe.html