My mom makes some weird version... it's hamburger with seasoning around the casserole dish, then has seasoned potato filling on the inside. Top with the seasoned hamburger and bake it. Drain the fat from the burger off as it bakes.

When I want sheperd's pie, I go to WaWa, and get theirs... it's basically beef stew on top of mashed potatoes. It's comfort food, and I like their version.