St. Stephen's Day Pie
Cottage pie or shepherd's pie is a meat pie with a crust of mashed potato.
In early cookery books, the dish was a means of using leftover roasted meat of any kind, and the pie dish was lined with mashed potato as well as having a mashed potato crust on top.
The term "shepherd's pie" did not appear until 1877, and since then it has been used synonymously with "cottage pie", regardless of whether the principal ingredient was beef or mutton. More recently, the term "shepherd's pie" has been used when the meat is lamb, the theory being that shepherds are concerned with sheep and not cattle (see folk etymology).