Place the diced sushi-grade tuna in a chilled bowl. In a small bowl whisk together soy sauce, sesame oil, rice vinegar, mayonnaise and sriracha until smooth.

Pour the dressing over the diced tuna and gently fold to coat evenly. Stir in sliced green onion, toasted sesame seeds, sea salt and black pepper. Taste and adjust seasoning (add a little more soy for saltiness or extra sriracha for heat). Cover and refrigerate while you prepare other components, at least 10 minutes but no more than 30 minutes for best texture.

Pickled Cucumber

Combine rice vinegar, sugar and salt in a small bowl and stir until sugar dissolves. Add the thinly sliced cucumber half-moons and toss to coat. Let sit at room temperature for 10 minutes (or refrigerate up to 1 hour). Drain excess liquid before assembling.

Cone & Fillings

If using wonton cones that need crisping, bake or fry according to package instructions and let cool. If using seaweed cones, keep them sealed until assembly to maintain crispness.

Season and warm the cooked sushi rice if desired slightly (microwave 15–20 seconds). Using lightly oiled hands or wet spoon, portion about 2 tablespoons (roughly 2 tablespoons = 1/8 cup) of rice into the bottom of each cone to create a base layer — this prevents sogginess and provides structure. Total rice amount should fill 8 cones modestly.

Top the rice in each cone with a small layer (about 1 tablespoon) of pickled cucumber, then add 2 tablespoons of the marinated tuna poke mixture. Gently press in half-tablespoon of diced avocado beside or on top of the tuna. If using masago/tobiko, sprinkle about 1/4 teaspoon over each cone.

Finishing & Garnish

Drizzle each cone lightly with unagi sauce or a few drops of extra soy reduction (about 1/4 tsp per cone) if using. Scatter microgreens or cilantro on top and finish with the remaining toasted sesame seeds.

Serve immediately on a standing cone rack or a platter with the open side up. Recommend serving within 20 minutes of assembly to keep cones crisp.