In a medium bowl, combine 3 tbs Japanese mayonnaise, 1.5 tsp Sriracha, 0.5 tsp chili garlic sauce (if using), 0.5 tsp toasted sesame oil, 0.25 tsp kosher salt and 1/8 tsp black pepper. Whisk until smooth.

Add 1.5 cups flaked crab and 2 tbsp thinly sliced green onions to the mayo mixture. Fold gently until the crab is evenly coated but still chunky.

Fold in 2 tbsp crispy tempura bits or panko just before plating to retain texture. Taste and adjust seasoning (more Sriracha for heat, more mayo for creaminess). Cover and refrigerate while preparing other components (up to 30 minutes).

Avocado Layer

Halve, pit and scoop the flesh of 1 ripe avocado into a bowl. Add 1 tsp fresh lime juice, 1/8 tsp sea salt and a pinch (1/16 tsp) black pepper.

Using a fork, gently mash the avocado to a smooth but slightly chunky consistency. The texture should hold shape when scooped. Adjust seasoning to taste.

If not assembling immediately, press plastic wrap directly onto the avocado surface and refrigerate up to 30 minutes to prevent browning.

Fresh Tuna Topping

Ensure tuna is very fresh and kept chilled. Dice tuna into small uniform 1/4-inch pieces and place into a small chilled bowl.

Add 1 tsp soy sauce, 1/4 tsp sesame oil and 1 tbsp thinly sliced scallions to the diced tuna. Toss gently to coat. Sprinkle 1/2 tsp toasted sesame seeds and fold once. Keep chilled until assembly.

Assembly & Garnish

Choose individual serving plates or a single serving ring mold (2.5–3 inches wide). If using a ring mold, lightly oil the inside so mixture releases cleanly.

Place the ring mold in the center of the plate. Spoon or pack 1/3 of the spicy crab mix into the bottom of the mold and press lightly to form an even base layer.

Add a layer of mashed avocado on top of the crab: spoon in about 1/2 of the mashed avocado and gently press to create a neat middle layer (about 3/8 inch thick). Smooth the surface with the back of a spoon.

Top the avocado with the remaining crab mix if you prefer a double crab layer, or proceed directly to the fresh tuna. Spoon the diced tuna mixture onto the top, mounding slightly. For a classic stacked look: crab base, avocado middle, fresh tuna crown.

Carefully lift the ring mold straight up to release the stack. If edges need cleaning, wipe gently with a damp paper towel.

Garnish with 1 tbsp microgreens or cilantro, a drizzle of 2 tbsp wasabi or spicy mayo around the plate, a sprinkle of additional toasted sesame seeds, and optional nori strips or lemon/lime slices. Serve immediately with pickled ginger on the side.

Serve chilled. Advise consuming within 30 minutes of assembly for best texture and flavor, especially with raw tuna.