1To prepare the dashi for ponzu, combine 100 grams of Water and 2 grams of Kombu in a small saucepan. Heat gently over low heat, removing the Kombu just before the water boils. Add 5 grams of Katsuobushi, remove from heat, and let steep for 30 seconds. Strain the dashi through a fine-mesh sieve, discarding the Katsuobushi.
2Combine the prepared dashi with 50 grams of Koikuchi soy sauce, 25 grams of Mirin, and 25 grams of Rice vinegar to create the ponzu sauce. Set aside.