Preheat the oven to 180 ° C.
Peel the turnips and cut them into slices 4 to 5 mm thick. Steam them under pressure for 5 minutes or for fifteen minutes in a pot of water. They should be tender while retaining their consistency. If they are cooked too long, they will mash.
In a frying pan with oil, sauté the onion cut into thin strips until they become translucent.
Then add the salmon cut into cubes without the skin (which can be used to make a crisps by frying it in a hot pan with oil). Season with salt and pepper.
After one or two minutes, add the white wine then let the alcohol evaporate before adding the liquid cream. Simmer for a few minutes
In an oven dish, place a first layer of turnips, half of the smoked salmon cut into strips then half the preparation with the salmon.
Make a second identical layer then add a last layer of turnip.
Add the reblochon on top and cook for 20 minutes at 180 ° C. It is possible to put in grill mode for 5 to 10 minutes to obtain a golden cheese.