01 - Rinse sushi rice under cold water until water runs clear. Combine rice and water in a saucepan, bring to a boil, then cover and simmer on low for 18 minutes. Remove from heat and let stand, covered, for 10 minutes.
02 - In a small bowl, mix rice vinegar, sugar, and salt until dissolved. Gently fold this mixture into the cooked rice. Let cool to room temperature before assembling.
03 - In a medium bowl, whisk together mayonnaise, Sriracha, sesame oil, soy sauce, and lime juice. Add diced tuna and toss gently to coat evenly. Keep refrigerated until ready to serve.
04 - In a small bowl, combine soy sauce, rice vinegar, honey, and sesame oil. Stir until honey is fully incorporated. Set aside for drizzling.
05 - Divide seasoned rice among four bowls. Arrange spicy tuna, mango, avocado, cucumber, carrot, and pickled ginger on top of the rice in sections.
06 - Drizzle with soy dressing. Garnish with spring onions, sesame seeds, crispy fried onions, and nori strips. Serve immediately while tuna is cold and rice is at room temperature.