First of all, this meal started out as a pot pie. The "baby boy" came in - he does not like pot pie. When he walked in from school and smelled the chickens boiling, he said, "Oh boy, we're having dumplings!" We weren't,but I know that in a pinch, a pie crust can result in a dumpling!
In a stock pot, cover chickens with water - add salt to taste (I use a couple of tablespoons for a large pot). Add onions and celery and bring to a boil. Simmer until chicken falls off the bone. Set aside to cool.

Make pie crust, or roll out refrigerated crust. Line the bottom of a casserole with crust. Let crust overlap the sides of the casserole dish.
Make a roux of 2 tbsp butter and 3 -4 tbsp of flour. Cook until lightly browned, whisking constantly. Add milk. Continue to whisk constantly while adding chicken broth until sauce is a medium consistency. Add salt and pepper to taste.
In casserole dish, layer chicken, vegetables, and potatoes, repeat. Cover with white sauce. Top with pie crust.
Cover with foil and bake for 20 minutes at 350. Remove foil and bake for 30 minutes, or until golden brown.