North America

This actually depends on where you live.Originally the dish was called Cottage Pie that was used as far back as 1791 and the meat source in the pie was any meat source that was available at the time.The term Shepherds pie did not make an appearance until 1877 and it's been used synonymously with the term Cottage Pie regardless of whether the meat was beef or mutton.In the UK, Cottage pie is typically made with beef, while Shepherds pie is made with lamb.In, Shepherd's pie is made with beef, and the term Cottage pie is very rarely used.