Butter pie
A butter pie is a traditional English savoury pie consisting mainly of onions and potatoes. It is also sometimes served on a savoury barm cake. The pie is stocked by chip shops, sandwich shops, local corner shops and some supermarkets within Lancashire. It is also known as Catholic pie, Friday pie, air pie or a special. The pie is known to have been created for workers from Lancashire's Catholic community, to consume on days when meat could not be eaten.
Source: Wikipedia
