It’s often served with garden peas.
If the dish is made with a meat other than lamb or mutton, it is actually a Cottage Pie.
Using pre-ground meat from the store meat counter in the pie is usual now, but it can turn into hard little pellets on you.
Instead of ground meat, try using chunks of meat from shoulder of lamb, or beef shank. Leave some fat on, to help prevent the meat from going dry on you.
Cook the chunks of meat first until tender, and then proceed to assemble the pie.
The mashed potato on top should have lots of butter and milk in it. Ideally, they’re not mashed too smoothly.
Shepherd’s Pie probably originated in Scotland and in the north of England. Originally, it was made from chunks of meat, probably leftover from a roast, as mincing machines weren’t invented until the 1870s.
The dish as we know it, though, couldn’t have originated before potatoes became generally accepted in the UK, which wasn’t until the end of the 1700s.
Before that, the dish or a very similar one was made in Scotland, but topped with a pastry crust instead of mashed potato.
The name for the dish appeared in the 1870s.
Parker Bowles, Tom. Why there’s no better British dish than shepherd’s pie. London: Daily Mail. 17 September 2009.