Tachiuo, or Silver Beltfish, is a member of the cutlassfish family, and is season in Japan during the summer. Whilst served as sushi, it is not a fish typical to Edomae-style sushi as it was not caught in Tokyo Bay and served back then. However, it is served in high end sushi restaurants nowadays nonetheless.
The long silver body of the fish resembles a sword, which is where it’s name originates from, with the character 刀 in 太刀魚 meaning knife. Thought typically a meter in length, it can grow up to two meters. The skin of the fish is shiny but it is still classified as a white fish (Shiromi/白身). The skin of the fish is fragile and can easily stain your chopping board with a silver hue if the fish is pressed. Therefore, care must be taken when cutting the fish as not to damage it’s skin.
Whilst the skin of the fish is soft, larger Tachiuo have thicker skin which would normally then be blowtorched (aburi/炙り). We do not blowtorch fish in the restaurant as we believe it imparts the taste of gas on the fridge. Instead, we marinade the fish lightly in white miso for around a day before lightly grilling the skin on charcoal. The taste of Tachiuo is more robust and meat like, which allows it to stand up to stronger flavours like miso and grilling.
Tachiuo Sushi Preparation Method:
First, start by cutting of the head of the Tachiuo. It does not have any scales.
Make a slit along the belly of the fish and remove the internal organs of the fish. Wash the inside with water and wipe dry with a paper towel.
Section the fish into manageable portions of around 15 to 20cm each.
For the belly section, begin filleting the fish by breaking the rib bones through the belly cavity.
Then, make a cut along the back of the fish and continue cutting the fish until the fillet is released.
Remove the ribs bones and pin bones from the fillet.
Repeat for the other segments of the fish.
If blowtorching (aburi/炙り) the skin of the fish and not the white flesh.