The main ingredient in traditional shepherd's pie is minced lamb. This savory dish consists of a layer of lamb cooked with vegetables and gravy, topped with a generous layer of mashed potatoes. The use of minced lamb is significant to its identity, distinguishing it from similar dishes like cottage pie, which typically uses minced beef. Shepherd's pie is often seasoned with herbs like rosemary and thyme, enhancing its flavors. It’s a comforting, hearty meal commonly enjoyed in British cuisine, reflecting the agricultural landscape and the history of utilizing leftover meats in home cooking.