Preheat oven to 350 degrees
You can use leftover chicken or boil 2 to 3 chicken breasts until cooked through. Cool, then chop or shred chicken.
Whisk together cream of celery soup and chicken broth in a sauce pan over medium heat. I never measure, but you'll probably need a 1/2 can or a can of broth. Just mix until the gravy is the desired consistency.
Add a half bag (or more, to taste) of mixed vegetables to soup mixture. You may need to add more broth, especially if you like a creamy pot pie like I do.)