Preheat the oven to 400°F (200°C).

Dice the ham, onion, and garlic.

In a skillet, melt 4 tablespoons (60 g) of butter and sauté the onion. In another pan, cook the sliced mushrooms until they release their liquid.

Once the onions are lightly browned, add the mushrooms and cook until slightly golden.

Add the garlic and ham, sauté for one minute, then remove from heat.

Cook the gnocchi according to package instructions.

For the béchamel sauce:

In a saucepan, melt 3.5 tablespoons (50 g) of butter, then add 6 tablespoons (50 g) of flour. Gradually add the milk in three parts, whisking vigorously to avoid lumps.

Cook until the béchamel is thick and smooth.

Remove from heat and stir in a little shredded Swiss cheese. Season with salt and pepper.

After ten minutes, add the egg yolks.

Then add the gnocchi, mushroom, ham, and onion mixture. Stir in the chives.

Pour everything into a baking dish and top with the remaining shredded Swiss cheese.

Bake for 20 minutes at 400°F (200°C).