Prepare a mashed potatoes: peel the potatoes, wash them, cut them into pieces, boil them in salted water. Drain and mash the potatoes, stir in the milk, season with salt and nutmeg.
Fry the minced meat in margarine until brown, place on a plate, fry the onion rings in the frying fat until golden.
Wash the cauliflower, cut into florets, add to the boiling salted water and cook for about 7 minutes.
Layer everything in a baking dish: first the mashed potatoes, then the minced meat with the frying fat and the onions, and the cauliflower on top. Finally, the grated cheese is sprinkled on the casserole.