Lay out some of the jacket potatoes in a greased baking dish like a roof tile and sprinkle cheese over them. Proceed in this way until all the ingredients have been used up. Last layer should be cheese.
Topping: whisk the cream, sour cream, egg, parsley and onion, salt and pepper and pour over the potatoes.
Bake for 45 minutes at 200 degrees.
Hearty cheese variant: partially replace the Emmentaler with sheep`s cheese.
Cast variant: 1/2 Lt. Milk and 2 eggs and possibly herbs from Provence.