Cut the potatoes into small slices (about 3-4mm will do - the large slicer on one side of a grater works well for this) and spread them in the oven dish
Sprinkle rosemary, salt, pepper and nutmeg on the potatoes. Be generous with all of it.
Grate the garlic and sprinkle it evenly on the potatoes as well
Optional: Get a pot, heat up the cream and throw in the cheese. Wait until the cheese is melted. Then pour evenly over the potatoes.
Or just pour the cream over without heating up and layer the cheese on top. It will taste similar but not look quite as beautiful.
Pop the dish into the oven for 40 minutes.
Check back after 30 minutes to make sure the cheese isn’t burning. If it is, reduce the heat and add an aluminum foil cover for the last 10 minutes.