Bonito flakes, also known as katsuobushi, are made by shaving dried, fermented skipjack tuna thinly using a kezuriki, a traditional wooden shaving box. Hana-katsuo is used to describe these particularly thin shavings of bonito. Thin shavings of bonito flakes are often steeped briefly in boiling water to make exceptional quality broth (dashi) or is traditionally used as a topping for dishes such as okonomiyaki, takoyaki, and yakisoba.
Uses: Make a simple dashi by bringing 10g of kombu and 1000g of water to a boil. Add 10g of katsuobushi and let steep off the heat for 60 seconds and then strain. The solids can be discarded or repurposed for another use such as homemade furikake.