Hazırlanışı
1Begin by preparing the dashi stock. Place the Kombu in a pot with Water for dashi and let it soak for 30 minutes. Bring the water slowly to just below a boil over medium heat. Remove the Kombu just before the water boils.
2Add the Katsuobushi to the simmering dashi water. Turn off the heat immediately and let the Katsuobushi steep for 5 minutes. Strain the dashi through a fine-mesh sieve, discarding the Katsuobushi, to obtain a clear dashi stock.
3Return the strained dashi stock to the pot. Add Usukuchi soy sauce, Mirin, Sake, and Salt. Bring the broth to a gentle simmer over medium-low heat, then turn off the heat. This is your tsuyu (udon broth).