Mix beef with egg,bread crumbs,salt,herbs,mustard,cumin and garlic powder.Pat evenly into a 23 cm pie pan to make a crust.Fill crust with a layer of potatoes,onion and mushrooms,reserving some mushrooms to ring the pie.Cover with foil.Bake @ 180ºC or 1 hour or until potatoes are done.Remove from oven.Remove foil.Top with cheese and sprinkle with parsley.Return to oven just long enough to melt cheese.