This Japanese hot pot is delicious, comforting, and good for what ails you. You can switch out the mushrooms and vegetables for other things you have on hand!
Combine the kombu, shiitake mushrooms, and water in a pot and let them soak for 30 minutes.
Cover the pot and set it over medium heat. Just before the stock comes to a simmer, remove the kombu.
Once the water comes to a boil, let the stock simmer for 5 minutes. Then remove the pot from the heat and let the stock steep for 3 minutes. Then strain it through a fine-mesh sieve lined with 2 layers of cheesecloth. Do not discard the shiitake mushrooms!
Combine the dashi sake, mirin, and soy sauce in a bowl. Set it aside.
Cut off and discard the shiitake stems. Set the caps aside.
Put the bottom pieces of the napa cabbage on the bottom of the donabe (claypot) or sauté pan. Arrange the other ingredients on top of the cabbage, in separate neat bundles.
Gently pour in the reserved broth.
Cover the donabe and bring the broth to a boil over high heat. Decrease the heat to medium and let simmer for several minutes until things start to soften, then uncover the pot, and simmer until the ingredients are tender.
Transfer the donabe to the table. Serve the donabe ingredients and broth in small bowls. Garnish with ponzu, grated daikon, thinly sliced scallions, shichimi togarashi, and/or yuzu koshou, as desired.