01 - Place sushi rice in a fine-mesh strainer and rinse under cold running water, gently swirling until the runoff turns completely clear. Transfer to a rice cooker or saucepan, add 2 cups of water, and cook according to package directions until tender and all liquid is absorbed.
02 - While the rice is still hot, stir together rice vinegar, sugar, and salt in a small bowl. Microwave for about 20 seconds until the sugar and salt dissolve completely. Pour the seasoned vinegar over the warm rice and fold gently with a spatula, taking care not to mash the grains. Let the rice cool to room temperature.
03 - Shred or chop the imitation crab into bite-sized pieces. Dice the avocado and seeded cucumber into uniform cubes. Slice the green onions thinly on a bias. Cut the roasted nori sheets into thin strips using scissors or a sharp knife.
04 - Combine Japanese mayonnaise with sriracha in a small bowl and whisk until smooth and evenly blended. Adjust the amount of sriracha to your preferred heat level.
05 - Divide the seasoned sushi rice evenly among 4 bowls. Arrange the imitation crab, diced avocado, cucumber, nori strips, and pickled ginger in sections over each bed of rice. Drizzle with the spicy mayo and finish with a generous sprinkle of toasted sesame seeds and sliced green onions.
06 - Serve immediately with soy sauce and wasabi on the side so each diner can season to taste.