Keep otoro very cold. Pat dry with paper towel, trim any sinew, then using a sharp knife cut into small 1/8–1/4 inch dice. Transfer to a chilled bowl and return to refrigerator while you prepare other components.

Aromatic mix

Combine finely diced shallot and sliced chives in a small bowl. Add the grated yuzu or lemon zest, toasted sesame seeds, kosher salt and black pepper. Stir to combine and chill briefly (1–2 minutes) to let flavors marry.

Seasoning & Dressing (C)

Make the dressing

In a separate small bowl whisk together light soy sauce, rice vinegar, mirin, toasted sesame oil, extra-virgin olive oil and wasabi paste until slightly emulsified. Taste and adjust: add more soy for saltiness, more wasabi for heat, or a few drops of rice vinegar for brightness.

Combine tartare

Remove the diced otoro from the refrigerator. Gently fold the aromatic mix into the otoro, then pour the dressing over the fish. Use a rubber spatula to combine carefully — avoid mashing; you want distinct pieces. Fold in optional fish roe if using. Check seasoning and add a tiny pinch more salt or a few drops of soy if needed.

Plating & Accompaniments

Forming and plating: Use a 2.5–3 inch round ring mold (optional) placed on chilled plates. Spoon the tartare mixture into the mold, pressing gently to hold shape, then lift mold straight up. If no mold, pile the tartare with a spoon for a rustic look.

Garnish: Top with microgreens or baby mizuna, a small sprinkle of toasted nori strips or furikake, and an extra pinch of sesame seeds. Arrange thin cucumber slices and crispy wonton chips or toasted sesame crackers alongside for scooping.

Serve immediately: Keep portions small and serve cold. Otoro is rich—this dish is best enjoyed right away to preserve texture and flavor.