Shiru Gohan

Gently wipe the kombu with a damp cloth. Place the kombu and 600g water in a medium pot. Heat over medium-low heat. Just before the water boils and small bubbles appear, remove the kombu.

Bring the water to a boil, then immediately turn off the heat. Add the katsuobushi to the hot water. Let it steep for 30 seconds to 1 minute, then strain the dashi through a fine-mesh sieve, discarding the katsuobushi.

Return the strained dashi to the pot. Add the usukuchi soy sauce, mirin, sake, and salt. Heat over low heat until just simmering, ensuring not to boil vigorously.