Tail belly at 60 degrees: Simmered · 597

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. Scraped from the sinew with a spoon and folded through chopped spring onion, it makes the best gunkan topping there is.

Graded by scrape yield and freshness, not a fat stamp. Colour, sinew, where the fat sits, and thickness are what you check before you pay. Ask for the thickness that matches “Simmered.” Use 60 degrees and 60 when you cook. Salt after you know the job. Do not play with undercooked meat.

Cook Tail belly to 60 degrees and serve it as “Simmered.” The other figure to watch is 60. Do not time a hard-working muscle like a thin steak. Colour before heat is not doneness. The flesh between the sinews should look bright and glossy, never dull. A cut’s grain comes from how much the muscle worked. Tail belly needs heat through to 60 degrees before “Simmered” makes sense. 60 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.