Hirame Flounder Flat Fish Technique
Japan (nationwide coastal; particularly Tsugaru Strait, Sanriku coast for premium specimens)
Hirame (平目, olive flounder) is one of the most highly prized white fish in Japanese cuisine for its supreme delicacy and the unique engawa — the small, firm, richly flavoured fin muscle running along the outer edge of each side. The fish is flat-bodied and typically butchered using the go-mai oroshi five-piece filleting method: two upper fillets, two lower fillets, and the central carcass — a technique distinct from the standard sanmai oroshi (three-piece) used for round fish. Hirame sashimi is cut in flat, wide slices (hira-zukuri) to showcase its translucent, almost crystalline white flesh, which is firmer and more delicate in flavour than madai. The engawa, served separately, has a chewy, fat-rich texture that Japanese diners prize at sushi counters — typically seared lightly (炙り aburi) or served with ponzu and grated daikon. Winter hirame, caught October through February, is considered peak season (shun) because the fish accumulates fat reserves. Kobujime preparation — layering fillets between konbu sheets in the refrigerator for up to 8 hours — is particularly effective with hirame, firming the flesh and adding gentle umami depth. Hirame no ara (carcass and head) produces a delicate, sweet dashi or can be salt-grilled to extract the rich collar meat.