01 - Rinse the rice under cold water until the water runs clear. Combine rice and water in a saucepan. Bring to a boil, cover, reduce heat, and simmer for 18–20 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 into the cooked rice. Allow rice to cool to room temperature.
03 - In a bowl, mix soy sauce, sesame oil, sriracha, mayonnaise, rice vinegar, honey, garlic, and ginger. Add the diced tuna and gently mix to coat. Refrigerate for at least 10 minutes to marinate.
04 - Slice avocado, cucumber, carrots, radishes, and scallions.
05 - Divide the seasoned rice among 4 bowls. Top with marinated tuna, avocado, cucumber, carrots, radishes, and scallions. Sprinkle with sesame seeds, nori strips, and any optional toppings.
06 - Serve immediately, garnished with extra chili slices or pickled ginger if desired.