I hate those 'steak pies' which are just a stew with a piece of puff pastry placed on top. Soon after they started to appear, I asked a Trading Standards Officer how they could be called a pie. He felt the same way as I did, but said that they could do nothing about it, since for what constitutes a pie has never been legally defined.
It seems the reason that bars and restaurants prefer to serve up these so-called 'pies' is that a stew is allowed to be re-frozen, but if it's encased in pastry in the form of a traditional pie, re-freezing is not permitted.