Bluefin Tuna-caviar Recipe

Preheat the oven to 325°F (160°C). Line a baking sheet with parchment paper.

Cut each nori sheet in half crosswise to create six rectangles. Combine the flour and cornstarch in a small bowl, whisk in the cold water until a smooth, thin batter forms, then stir in sesame oil.

Using a pastry brush or back of a spoon, lightly brush a thin, even coat of neutral oil onto one side of each nori rectangle. Brush the batter thinly over the oiled side of each nori—this helps crisping and gives slight sheen. Optionally sprinkle toasted sesame seeds very sparingly.

Place the nori rectangles on the prepared baking sheet, batter side up. Bake 6–8 minutes until edges curl slightly and nori is crisp but not burned. Watch carefully; baking time varies. Remove and transfer to a cooling rack to crisp fully (they will harden as they cool).

Keep the tuna cold until ready. Pat the tuna dry with paper towels. Trim any sinew and cut into very small uniform dice (about 3–4 mm pieces) for a delicate tartare texture.

In a chilled bowl, combine the minced shallot, chives, lemon zest, lime juice, soy sauce, and sesame oil. Stir to blend.

Add the diced tuna to the bowl and gently fold to coat—avoid over-mixing. Add the neutral oil and adjust seasoning with fine sea salt and white pepper. Taste and adjust acid or salt as necessary. Refrigerate the tartare (covered) for up to 15 minutes to let flavors marry; do not leave raw fish at room temperature for extended periods.

Place the dried wakame or kombu flakes in a small bowl and pour the hot water over them. Let steep 5 minutes until rehydrated and flavorful, then strain, reserving the soaking liquid. Finely chop or blitz the rehydrated seaweed.

In a blender or using an immersion blender, combine the rehydrated seaweed, 15 ml of the reserved soaking liquid, the mayonnaise, lemon juice and salt. With the blender running, slowly stream in the 40 ml grapeseed oil until a smooth, creamy emulsion forms. If too thick, thin with up to 1–2 tsp additional soaking liquid. Adjust seasoning and chill briefly.

Place one nori crisp on a serving plate. Spoon 1–1.5 tablespoons of the seaweed emulsion onto the crisp and gently spread a small round (use a 1.5 inch ring mold if desired) of tuna tartare (about 1.5–2 tablespoons) on top of the emulsion so it sits stably.

Using a small spoon, gently nestle about 1/2 teaspoon of chilled Osetra caviar atop each portion of tartare. Finish with a tiny drizzle (a few drops) of sesame oil if desired and a few microgreens for color. Repeat to make 6 canapés (or adjust per serving).

Serve immediately so nori crisps remain crunchy. Provide lemon wedges on the side for guests to squeeze lightly if desired.