A Pie in Britain is usually understood as being completely surrounded by pastry. There are specific pies such as steak and kidney which are what the Americans would call a pot pie. I'm reminded of the most difficult dish I've ever eaten - Seafood Soup en Croute in the Chester Pierre Victoire (RIP). The soup plate had the pastry baked onto it, and underneath, the seafood was still in its shells! It was delicious though.