Gnocchi with Castelmagno cheese

Boil the potatoes in their skins until very tender when pierced with a fork. Drain them, then peel them while still warm.

Pass the warm, peeled potatoes through a potato ricer or mash them thoroughly on a clean work surface. Allow the mashed potatoes to cool slightly to release steam, about 10 minutes.

Form a well in the center of the mashed potatoes. Add the 00 flour, fine sea salt, and egg yolk into the well.