Bonito flakes - Usu Kezuri

Bonito, also known as bluefish, belongs to the mackerel family and is a type of tuna. It is very important in Japanese cuisine, but is rarely used as a sushi topping due to its distinct flavour and is more often used as a condiment in the form of flakes (katsuo bushi). To produce the bonito, it is first boiled, then smoked and dried several times until it is very hard. The flakes are then scraped off the fish with a special slicer and are mainly used for soups, such as dashi broth, because of their strong, salty flavour.