Negima Nabe Leek and Fish Hotpot Edo Tradition

Negima nabe (葱鮪鍋, 'leek-tuna hotpot') is an Edo-period Tokyo hotpot tradition that originated as working-class fishmonger and riverside market cuisine — a practical use of fatty tuna trimmings (parts considered low-grade by sushi standards but prized for their rich fat content in simmered preparations) combined with negi (long green onions/leeks). The dish exemplifies Edo pragmatism: parts of the fish too oily for raw consumption (toro belly, collar, dark flesh near the spine) that would otherwise be discarded or sold cheaply were combined with the sweetness of deeply simmered negi to create a winter hotpot of extraordinary depth. The broth is typically a strong dashi with soy and sake; the negi are added first and cooked until completely softened to sweetness, then the fatty tuna pieces are added briefly — just enough to set but not fully cooked through, retaining a pink centre. The fat from the tuna disperses into the broth, enriching it further. Premium versions at traditional Tokyo negima nabe restaurants use hon-maguro (Pacific bluefin) trimmings, and the long simmered negi softened to near-dissolving is as essential as the fish. The dish is closely associated with the culture of Tokyo shitamachi (low city) merchant neighbourhoods.