Potato and smoked salmon gratin

Peel the potatoes and cut them into thin rounds, about 3 mm thick. Set them aside in a mixing bowl of cold water so they don't turn dark.

Cut the onion into small dice. In the nonstick skillet, melt 10 g of butter over medium heat. Add the onion and sauté it for 5 min until translucent.

Drain the potatoes and add them to the skillet with the onion. Cook them 5 min over medium heat, stirring now and then, without browning them.

In the saucepan, warm the milk and crème fraîche over low heat without boiling. Off the heat, add the nutmeg, half the shredded cheese (25 g), salt and pepper. Mix well.

Preheat the oven to 180°C (thermostat 6). In the baking dish, spread half the potatoes and onions. Add half the smoked salmon, cut into pieces. Cover with the rest of the potatoes and salmon.

Spread the hot sauce evenly over the gratin. Sprinkle with the rest of the shredded cheese (25 g).

Bake the gratin for 20 min, until the top is nicely browned and the potatoes are tender.