Chicken Pot Pie

1 lb. skinless,boneless chicken breast halves-cubed
or use leftover roasted chicken meat,remove skin and bones diced
1/3c.butter
1/2c.diced celery                                        optional: kosher salt,pepper
1/2c.diced carrots
1/2c. diced potatoes                                          
1/3c.diced onion
1/2t.salt and 1/4 t. black pepper 
1/2t. poultry seasoning                     
1 3/4c.chicken broth
2/3c. evaporated milk or low fat milk
1/3c. all purpose flour
1 egg  white beaten   or milk for brushing
2(9 inch)unbaked pie crusts

1. Preheat oven to 425 F(220C)
2. In a saucepan,combine all veggies and cubed chicken meat,add water and cook for 10 minutes.Remove from heat drain and set aside.
3.Using the same saucepan, in a medium heat cook onions and butter until soft and translucent.Stir in flour,salt,pepper,poultry seasoning.Slowly stir in chicken broth and milk.Simmer over medium heat low until thick. Set aside.
4.Place the chicken and veggie mixture at the bottom of the pie crust.Pour hot liquid over it.Cover with top crust,seal,flute the edges and cut the excess dough.Make several small slit on top to allow steam to escape and brush  it with a little milk or beaten egg white. Sprinkle a little kosher salt and coursely ground pepper.
5.Bake in preheated oven to 30-35 minutes or until the pastry is golden brown and the filling is bubbly. Cool for 10 minutes before serving.