1To prepare the dashi, gently wipe the Kombu with a damp cloth, then place it in a pot with Water and let it soak for 30 minutes. Heat the pot over medium-low heat; just before the Water boils, remove the Kombu. Bring the Water to a boil, then turn off the heat and add the Katsuobushi. Let it steep for 30 seconds, then strain the dashi through a fine-mesh sieve, discarding the Katsuobushi.