Potato Gratin

Generously grease a 20x30 cm baking dish with butter.

In a saucepan, combine the cream with salt, pepper, and nutmeg, bring to a simmer, and remove from heat.

Wash the potatoes and slice them thinly.

Arrange the first layer of potatoes in the greased dish, overlapping them slightly.

Sprinkle the potatoes with a quarter of the grated cheese and pour a quarter of the warm cream over this layer.

Repeat the process with the remaining potatoes, cheese, and cream, adding a layer of mushrooms if desired.

Pour any remaining cream over the potatoes, making sure to reserve the cheese for later.

Bake in a preheated oven at 150 degrees Celsius for about an hour, covered with foil.

After an hour, remove the foil and test the potatoes for doneness with a knife.

Take the gratin out of the oven, top with the remaining cheese, and return to the oven for a few minutes until the cheese melts and forms a crust.