中なか落おち

noun

scraped meat from the spine of a fish or beef

Culinary term for the flesh left on the spine after filleting, especially tuna; often used in sushi or as a topping.

• マグロの中なか落おちを軍ぐん艦かん巻まきにしました。

  I made gunkan-maki with scraped tuna meat from the spine.