4 lb. potatoes
250g/½ lb. Pancetta or smoked bacon, cut in lardons
2 onions, finely chopped or sliced
1 whole Reblochon cheese (500g/1lb) (or grated Emmental)
2 cups crème fraîche
2 tbsp. butter
1 tbsp. olive oil
pinch nutmeg

1. Slice the potatoes thinly
2. Boil the sliced potatoes for about 5 minutes.
3. Sauté the onions in half the butter and the oil until soft.
4. Slice or chop the bacon.
5. Add the cut bacon and fry for 5 minutes more.
6. Grease a gratin dish with the remaining butter.
7. Put a layer of sliced potatoes on the bottom.
8. Season with salt and pepper.
9. Spread the cooked onions and bacon on top.
10. Pour half the crème fraîche on top.
11. Cut the Reblochon in half horizontally.
12. Place one half of the Reblochon cut side down on top of the mixture.  (Emmental should be  grated over.)
13. Add another layer of potatoes.
14. Season again.
15. Pour the remaining crème fraîche on top.
16. Put the remaining half of the Reblochon on top cut side down.
17. Sprinkle the nutmeg over.