Preparation

Rice koji—the same mold used to make sake, miso, and soy sauce—transforms egg yolks into something extraordinary over the course of a week. These amber gems, when mixed into gnocchi dough, create pasta that tastes like it's been aged in a cave for months.

Curing the Yolks

1. Spread half the koji in a shallow container. Make 6 indentations with the back of a spoon.
2. Carefully separate eggs, placing yolks in the koji wells. Cover completely with remaining koji.
3. Cover container and refrigerate for 7 days. The yolks will firm up and develop intense umami.
4. After 7 days, gently brush off koji. The yolks should be firm and slightly translucent.

Making the Gnocchi

1. Boil potatoes in their skins until tender. Drain, peel while hot, and rice through a potato ricer.
2. Grate the koji-cured yolks finely over the warm potato. Add whole eggs, flour, salt, and nutmeg.
3. Mix gently until just combined. The dough should be soft but workable.
4. On a floured surface, roll dough into long ropes about 2cm thick. Cut into 2cm pieces.
5. Roll each piece over a fork to create ridges, or leave as pillows.
6. Boil in salted water until they float (about 2-3 minutes).
7. Serve simply with brown butter and sage to let the funky yolk flavor shine.