Katsuobushi, a traditional ingredient in washoku, or Japanese cuisine, are fillets of katsuo (skipjack tuna) smoked and dried by a special process. The shaved flakes are used to make dashi stock for soup, and also eaten as a topping. Katsuobushi plays an essential role in bringing out the subtle flavors in washoku, and when this cusine was listed by UNESCO as an Intangible Cultural Heritage in 2013, it attracted attention worldwide. Chefs in many countries are now experimenting with katsuobushi in their local recipes. We visit Yaizu in Shizuoka, where they have been making katsuobushi the traditional way for over 300 years.