Tail belly at 90 degrees: Negitoro gunkan · 598

Scraped from the sinew with a spoon and folded through chopped spring onion, it makes the best gunkan topping there is. The belly towards the tail. It runs through with sinew, so it is scraped rather than sliced — this is the cut behind negitoro, the minced tuna and spring onion filling.

The flesh between the sinews should look bright and glossy, never dull. Colour, sinew, where the fat sits, and thickness are what you check before you pay. Ask for the thickness that matches “Negitoro gunkan.” Use 90 degrees and 90 when you cook. Salt after you know the job. Do not play with undercooked meat.

At the counter, read the use on Tail belly before the photograph. 90 degrees is the internal heat, “Negitoro gunkan” is the dish, and 90 is the stage of the fire. Marbling alone does not split stew from grill. Graded by scrape yield and freshness, not a fat stamp. A cut’s grain comes from how much the muscle worked. Tail belly needs heat through to 90 degrees before “Negitoro gunkan” makes sense. 90 is a stage of that heat, not a luxury score. The same cut becomes a stew, a grill, or a braise, so a steak minute does not cover a pot. Thick connective tissue wants time, not a hard sear alone. This is not medical advice.