Place the chicken broth into a dutch oven or large heavy bottom pot. Turn the heat on to medium.
Whisk in the cream of chicken soup and the cream of celery soup. Allow this to simmer for 10 minutes.
Stir in the frozen carrots, chicken, onion powder, garlic, salt, and pepper. Bring this to a boil.
Cut the tortillas into 1” squares, using a pizza cutter.
Gently add the tortillas to the soup. Press them down but do not stir vigorously as they will tear.
Bring to a boil again, then reduce heat, and allow to simmer for 15 minutes.
Remove from the heat. Gently stir in the milk.