Mix the cream, sour cream and hollandaise sauce in a saucepan over low heat (do not boil!). Season to taste with salt, pepper and nutmeg.
Lightly grease or oil a baking dish. Lay the potato slices in the baking dish, overlapping them, season with salt and pepper. Sprinkle some diced bacon and onion on top and pour some of the sauce over it. If you like, you can sprinkle a little grated cheese on top. This process is repeated until the desired layer height is reached or the potatoes are used up. Then distribute the remaining sauce over the potatoes. Scatter the cheese and breadcrumbs over the gratin.
Cook in a preheated oven at 200 ° C for about 1 hour. Serve hot.
Tip: If you want the cheese topping to be crispy, the grill or hot air function can also be switched on for 15 minutes.