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 rice vinegar, sugar, and salt in a small bowl until dissolved. Gently fold seasoning into warm rice using a cutting motion. Spread rice on a baking sheet to cool to room temperature.
03 - Moisten hands with water to prevent sticking. Form cooled rice into 12 compact rectangular or oval pieces, approximately 2 inches long and 3/4 inch thick. Arrange on a parchment-lined baking sheet.
04 - Refrigerate shaped rice for 20 minutes until firm. Cold rice maintains shape better during frying and develops superior texture.
05 - Combine diced salmon, mayonnaise, sriracha, soy sauce, green onion, sesame oil, and salt in a medium bowl. Mix gently to incorporate. Refrigerate until assembly time.
06 - Heat neutral oil in a large nonstick skillet over medium-high heat. Fry rice pieces in batches, cooking 2 to 3 minutes per side until golden brown and crispy throughout. Transfer to paper towels to drain excess oil.
07 - Place avocado slice on each crispy rice cake. Top with generous spoonful of spicy salmon mixture. Sprinkle with toasted sesame seeds and microgreens or chives.
08 - Arrange on serving platter with small bowl of soy sauce for dipping. Enjoy while rice remains crisp and salmon is cold.