boil potatoes untill almost cooked

slice potatoes into discs about 1/2 cm

in an oven proof dish arrange a layer of potatoes

put onion slices into rings and add a layer of rings

add a layer of cheese

than drizzle some cream and salt and pepper

keep layering and when done add a layer of grated cheese ontop

put in oven and remove when knife can be inserted easily and cheese has formed crust

also you can add bacon chives peppers pumpkin or carrot