Foryoueats: Chicken Pot Pie

1 pound skinless, boneless chicken breast halves - cubed

1 cup sliced carrots

1 cup frozen green peas

1/2 cup sliced celery

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

1 3/4 cups chicken broth

2/3 cup milk

2 (9 inch) unbaked pie crusts

Chicken Pot Pie