01 - Combine rinsed sushi rice and water in a saucepan. Bring to a boil, cover tightly, reduce heat to low, and simmer for 15 minutes. Remove from heat and let stand covered for 10 minutes to complete steaming.
02 - Whisk together rice vinegar, sugar, and salt in a small bowl until dissolved. Gently fold the seasoning mixture into the warm rice using a cutting motion. Spread rice in a shallow layer and let cool completely to room temperature.
03 - Moisten hands with water to prevent sticking. Shape cooled rice into 12 compact rectangular or oval pieces, approximately 2 inches long and 3/4 inch thick. Arrange pieces on a parchment-lined baking sheet.
04 - Refrigerate formed rice pieces for 20 minutes to firm up the texture, making them easier to fry and handle.
05 - Combine diced salmon, mayonnaise, sriracha, soy sauce, green onion, sesame oil, and salt in a mixing bowl. Fold gently to maintain texture. Refrigerate until assembly time.
06 - Heat oil in a large nonstick skillet over medium-high heat. Fry rice pieces in batches, cooking for 2 to 3 minutes per side until golden brown and crispy throughout. Transfer to paper towels to drain excess oil.
07 - Place a thin avocado slice on each crispy rice piece. Top with a generous spoonful of spicy salmon mixture. Garnish with toasted sesame seeds and microgreens or chives.
08 - Arrange assembled pieces on a serving platter and serve immediately with soy sauce on the side for dipping. Best enjoyed while rice remains crispy.