seasonal mushroom, koshihikari rice, egg yolk, black vinegar
Rinse the Koshihikari rice under cold water until the water runs clear. Soak for 30 minutes, then drain.
In a rice cooker or pot, combine the soaked rice with 250 ml of water. Cook according to the rice cooker's instructions or bring to a boil, then cover and simmer on low heat for 15 minutes. Remove from heat and let it sit, covered, for 10 minutes.
Clean the seasonal mushrooms and slice them as necessary. Set aside.
In a large pot, bring the dashi stock to a simmer. Add the soy sauce and mirin. Stir well.
Add the sliced mushrooms to the simmering broth and cook for about 5-7 minutes until tender.
In a bowl, place a serving of cooked Koshihikari rice. Ladle the mushroom soup over the rice. Top with a raw egg yolk and drizzle with black vinegar. Garnish with sliced green onions.