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