shepherd's pie

Dish made from minced lamb or mutton with a crust of mashed potato, baked. Cottage pie is made with minced beef.

A dish of cooked ground or diced meat (traditionally lamb or mutton) mixed with gravy (and sometimes vegetables) and topped with mashed potatoes. The pie is then baked until the mixture is hot and the potato "crust" browns. Shepherd's pie was originally created as an economical way to use leftovers from the ubiquitous "Sunday roast."

The noun has one meaning:

Meaning #1: pie of hash covered with mashed potatoes and browned in the oven