Heat up 200 g milk, 200 g cream, 50 g mushrooms, 8 g calcium gluconate, 2 g xanthan gum, 10 g gelatin, and salt, then blend until smooth. Pour the mixture into sphere molds and freeze until completely solid.

Blend 120 g egg yolks with 8 g sodium alginate. While blending, gradually add 500 g water until the mixture is completely smooth. Allow the bath to rest so any air bubbles can dissipate.

Place the frozen mushroom spheres into the alginate bath. As the spheres thaw, the calcium gluconate diffuses outward and reacts with the sodium alginate. This takes around 10 to 15 minutes.

This reaction forms a thin gel membrane around the outside of the sphere. Because the center remains frozen initially, the gel only develops on the surface.

The final result is a sphere with a thin jelly-like exterior and a creamy liquid center.