Trim the root ends of the shimeji mushrooms.

Slice the potato into 5mm thick pieces and soak in water for 5 minutes. Drain well.

Heat olive oil in a frying pan, add shimeji mushrooms and potato slices, season with salt and pepper, and sauté until golden. Transfer to a heatproof dish.

In the same pan, add milk, sake, and kombu tea powder. Bring to a boil and pour over the sautéed ingredients. Top with cheese and bake in a toaster oven for 6 minutes.