Gather all the ingredients.
Remove any dust or particles on kombu with a damp cloth (Never wash under running water!) but leave the white powdery substances which contribute to the umami flavor in the stock.
In donabe (Japanese clay pot), put dashi kombu and pour water till 70% full. Let the kombu soak for 1-2 hours. Or you can soak the kombu while cooking on the lowest heat for 15 minutes if you are in a hurry.
Meanwhile, make the sauce. Put sauce ingredients in a small sauce pan.
These leftover bonito flakes have a nice flavor and you can use it as filling for Okaka Onigiri.
When the kombu dashi stock is ready (after 1-2 hours), bring the stock to a boil on medium-high heat. Once boiling, add sake and salt.
When boiling again, cut the tofu to any size you like (whole tofu, halves, 6 pieces, etc) and put it in the kombu dashi stock.
Recipe by Namiko Chen of Just One Cookbook. All images and content on this site are copyright protected. Please do not use my images without my permission. If you’d like to share this recipe on your site, please re-write the recipe and link to this post as the original source. Thank you.