4: When nicely browned, return the potatoes to the pan, mix together and turn off the heat. Leave to wait in the pan.
5: Slice the tops off 4 hamburgers buns and use a fork to scoop out the interior crumb, which we will not be using this in this recipe.
6: Sit the buns and their "lids" on a baking sheet. Pop in the oven for 5 minutes, just to lightly colour the insides.
7: Meanwhile, pour 150 g cancoillotte into a small saucepan on low heat and heat through gently.
8: Put a bun on each plate and fill with the potato and bacon mixture.
9: Fill up with the hot cancoillotte.
10: Serve without delay, either as "surprise" bread with the lid on, or with the lid off at a jaunty angle, like in the photo.
Remarks
The inside of the burger buns removed in Step 5 isn't used in the recipe, but you can use it up in other ways, such as home-made breadcrumb coating. For a more golden-brown finish to the buns, use a brush to coat the insides with clarified butter before they go in the oven. Want to go the full Comtois? Use fried diced Morteau sausage instead of the bacon.