Rules of Pie
Pies are entirely encased in pastry.
If it is not entirely encased in pastry it can not be a pie. Therefore imposters such as Shepherd’s Pie, Cottage Pie and Lemon Meringue Pie are not pie!
The pastry should have been at least two distinct pieces before cooking.
Distinguishes baked goods like Cornish Pasties and Sausage Rolls from pies.
The pastry on top of a pie is allowed to have holes in it.
Allows for fancier presentation of pies and for venting.