katsuobushi
Katsuobushi is a fillet of skipjack tuna (sometimes referred to as a bonito) that has been simmered, smoked, sun-dried, and fermented until it becomes something akin to a piece of wood.
For tagging purposes use this tag for whole katsuobushi and for the thin shavings used as a garnish use the bonito flakes tag.
Examples
* !post #2054740: Chewing on whole katsuobushi
* !post #4372732: Shaving katsuobushi
External Links
* Wikipedia - Katsuobushi