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Ch?toro (???) is the name for medium fatty tuna when served in sushi restaurant. A bluefin tuna yields akami (red meat), ch?toro, and ?toro (???, pink fatty tuna). Ch?toro is usually found near the skin on the back and belly. It combines the lighter but deep, slightly bitter flavor of an akami with the sweet tenderness of an ?toro. It is quite expensive and usually served only on special occasions.
Video Ch?toro
References
Source of the article : Wikipedia