Prepare all the ingredients.
Peel the potatoes. Boil the potatoes.
When boiling, check is cooked by pocking with a knife. When the potatoes will be cooked, the blade should cut easily into the flesh.
When finished, drain and leave to cool (do not refresh!!!).
the onion...
...and in a bit of oil.
Add the smoked bacon..
...and sweat for a few more minutes.
Butter a gratin dish.
Cut half the potatoes in thick slices and cover the bottom of the dish with it.
Add half the onion and bacon.
Add the remaining sliced potatoes and the remmaining onion and bacon. Spread the cream on top.
Halve lengthwise the Reblochon and put on the potatoes (optional: add a glass of dry white wine).
Bake in a really warm oven (220-250°C or 428-482°F)...
Until the cheese melts and browns on the surface. Enjoy while it is warm!!!