From Bocuse in Your Kitchen
Suggestion: This dish is a meal itself; serve it with a green salad.
Variation: If you like, homemade tomato sauce or grated swiss cheese can be spread over the surface of the potatoes instead of butter before baking.
Boil the potatoes in lightly salted water for 30 minutes, then drain and puree in a food mill of mash until smooth. Add the milk, then beat in the egg, cheese, and a little salt, pepper, and nutmeg. Reserve.
Preheat the over to 400°F.
Place the chopped meat, onion, tomato paste, salt, and pepper in a mixing bowl. Beat together with a wooden spoon and reserve.
Butter a baking dish (preferably porcelain or enameled cast iron). Spread half of the mashed potatoes evenly over the bottom in a thick layer, then pour in the meat mixture and spread it out evenly over the potatoes. Pour in the remaining potatoes and use a fork to spread them over the meat and to decorate the surface by making lines and patterns over it.
Dot the surface with softened butter, then place in the oven and bake for 45 minutes or until brown on top.