1. Peel the potatoes, cut them into cubes, and plunge them into a pot of salted boiling water. Cook for about ten minutes. Drain and pat dry with paper towels.
2. Sauté the bacon in a hot pan.
3. Add the minced onion.
4. And the potatoes.
5. Remove the rind from the reblochon cheese and cut it into cubes. Pour the milk into a saucepan.
6. Melt the cubes of reblochon cheese in the milk.
7. Separate the egg whites from the yolks.
Work the yolks with the softened butter, salt, and pepper.
8. Add the flour and mix well.
9. Pour the reblochon cheese milk mixture into the preparation and mix well.
10. Beat the egg whites until stiff peaks form, then gently fold them into the reblochon cheese mixture.
11. Spread the bacon, onion, and potatoes on the bottom of a baking dish.
12. Pour the mixture over them.
13. Smooth the surface and bake for 45 minutes.
14. Let it set in the fridge for 2 hours before serving cold or reheated!