"Homemade" Chicken Pot Pie

I've had several requests for this recipe, and this is another one of Aaron's favorites that he requests often. The jist of this is frozen pie crusts, a can of chicken, can of veggies and then homemade sauce that just makes it yummy, yummy. I usually will just use 2 cans of chicken or a torn up rotisserie chicken and will make 2--one for now, and one to freeze.

INGREDIENTS:
2 (9 inch) unbaked pie crusts (I just get frozen crusts and let them thaw out)
1 can chicken (my classic White Trash Recipe ingredient) or chicken from a fresh rotisserie chicken
1 large can mixed veggies

SAUCE:
1/3 cup butter
1/3 cup chopped onion
1/3 cup all-purpose flour
1/2 teaspoon salt
1/4 teaspoon black pepper
1/4 teaspoon celery seed (I never have this on hand, so I don't use it)
1 can chicken broth
2/3 cup milk

DIRECTIONS:
1. Preheat oven to 425 degrees F (220 degrees C.)

2. Place chicken and veggies in thawed pie crust.

3. In the saucepan over medium heat, cook onions in butter until soft. Stir in flour, salt, pepper, and celery seed. Slowly stir in chicken broth and milk. Simmer over medium-low heat until thick.

4. Pour hot liquid mixture over. Cover with top crust, seal edges, and cut away excess dough. Make several small slits in the top to allow steam to escape.

5. Bake in the preheated oven for 30 to 35 minutes, or until pastry is golden brown and filling is bubbly. Cool for 10 minutes before serving.