Katsuo no Tataki

To prepare the ponzu, combine Koikuchi soy sauce, Rice vinegar, Mirin, Yuzu juice, Katsuobushi, and Kombu in a small bowl. Allow it to infuse for at least 30 minutes, then strain out the Katsuobushi and Kombu.

Pat the Bonito fillet very dry with paper towels. Sprinkle Sea salt evenly over all sides of the Bonito fillet.

Heat a heavy-bottomed pan or cast-iron skillet over very high heat until smoking. Sear the Bonito fillet for 15-20 seconds on each side, including the ends, until the exterior is lightly browned and crispy but the interior remains raw. Alternatively, use a kitchen torch to sear the surface of the Bonito fillet.