Tuna and spring onion. That is the entire contents. They simmer in a broth of soy sauce, sake, mirin and dashi, and nothing else is added to the pot at any point.

This was stall food, eaten standing up on a winter street. Tuna only became something people in Edo ate towards the end of the period, from the Tenpo years onward, and even then it was regarded with some suspicion. The fatty belly was considered coarse and could not be put in front of a guest, so it sat around until it spoiled and was then used as fertiliser or simply thrown out. The most valuable part of the fish, by our reckoning, was a disposal problem.

Townspeople worked out what to do with it. Simmered together with leek, the fish takes on the smell of the leek and the leek takes on the fat and the savour of the fish, and two cheap things improve each other in the pot. Neither would be worth eating alone. It was a stall dish, eaten standing up.

The part nobody wanted is now the part that costs the most, and this pot has become an expensive curiosity as a result. The name has not moved: negima is written exactly as it sounds, leek and tuna, and it still describes what is in the bowl.