Rice straw is set alight and burns hard and fast, and a block of bonito is turned over the flame for a matter of seconds. The heat never reaches the centre. Only the skin side takes it, and then the fish goes straight into cold water to stop it cooking any further.

Straw is used because a rice-growing province has it to hand at every season, and because it leaves a smell on the skin that charcoal does not. That smell is most of the reason anybody bothers with the fire at all.

There is a version done with salt. Coarse salt is pressed into the block before it goes over the flame, the fish is sliced while it is still warm, and the aromatics go on top: chopped spring onion, grated ginger, sliced raw garlic, thin rings of onion. On the board, the flat of the knife is used to press the seasoning down into the slices. The word tataki comes from that pressing rather than from the fire.

Several explanations circulate for how the dish began. A fisherman's meal cooked on deck; a domain lord banning raw fish, so people seared the outside and called it cooked; a precaution against parasites; a technique copied from Westerners grilling whale in the Meiji period. Every one of them sounds right, which is usually a sign that nobody knows.