Pink flakes of dried bonito (tuna), which are used in Japanese cooking as a garnish and in some cooked preparations, principally dashi. The tuna is boiled, smoked, then sun-dried. A special tool is used to flake the extremely hard chunks. Katsuobushi can be purchased in Asian markets and the specialty section of some large supermarkets. Depending on how fresh it is when purchased, it can be stored in a cool, dry place up to a year.