About Bonito: Many people might know bonito in its dried, flaky form and as the basis for dashi, the Japanese soup stock that is the foundation of miso soup. Bonito is an oily fish in the tuna, sardine, and mackerel family and is quite popular throughout the Mediterranean, where it is eaten fresh in many different dishes, from grilled to braised. Bonito has a firm dark or pinkish flesh with a delicious, if robust, flavor, which is stronger than white-fleshed fish.