Preheat oven to 400. Prepare a 9" pie pan with cooking spray; set aside. To prepare crust, add margarine, garlic powder, and eggs to hot rice. Spoon rice mixture into prepared pan. Press firmly across bottom and up sides of pie pan to form a crust. Layer half cup cheese and all of the tuna evenly over rice crust. Meanwhile to prepare filling, combine milk, remaining egg, salt, and black pepper. Pour over tuna mixture. Bake for 30 minutes or until center is set. Top with remaining cheese. Bake three minutes more or until cheese has melted.