Preheat oven to 450 degrees F. Boil chicken until fully cooked. Steam broccoli until tender. Mix together all the ingredients except pie crust, egg whites/butter, and 1/2 cup of the shredded cheese in a bowl.
Spray pie pan with non-stick cooking spray if your pan is not non-stick. Lay 1st pie crust in pie pan. Pour mixture into pie crust. Sprinkle 1/2 cup of shredded cheese on top of mixture. Lay 2nd pie crust on top of mixture and seal sides. Poke a few holes into top crust. Brush crust with egg whites or butter (optional).
Bake for 45 minutes to 1 hour until crust is golden brown.