Well, I think the distinction between cottage (beef) and shepherd's (lamb) survives in English kitchens and I still live here... But then the best so-called Shepherd's Pie I've made (or eaten) is Fay Maschler's version, which she calls one with Greek influences. Grated carrots, celery and onion are sauted with a little garlic before the lamb is added and browned. Then a whizzed tin of tomatoes is added, some ground cinnamon, dried oregano and fresh mint. The mixture is simmered for a long time. Covered with mashed potatoes and grated cheese and browned in the oven. Yes, this is rich and it is inauthentic but it is also very delicious.