Cook a large stewing hen (or you can use 2 large broilers) in enough water to cover, with a chopped onion, 2 celery stalks, 2 carrots and salt and pepper to taste. Cook until meat is very tender and will come off the bones easily.
Let cool in broth until just warm enough to handle. Remove meat from bones, discarding all skin, fat and gristle. Cut into bite-size chunks.
Line the bottom and sides of baking pan with the dough, rolled to a thin crust. It may tear, but just patch.
Put the cubed chicken in the crust-lined pan (NO VEGETABLES!).
Strain the broth and remove fat. Make a gravy of 4-5 cups of the broth, with enough flour dissolved in lukewarm water to thicken when stirred into the boiling broth. Let simmer until thickened.
Pour desired amount of the gravy over the chicken and mix in gently with a fork Adjust the seasonings.
Roll top pastry and cover the chicken mixture. Crimp edges and make several slits in the crust.
Bake in 400-degree oven for about 1 hour or until golden brown and bubbly.