01 - In a saucepan, combine rinsed sushi rice and water. Bring to a boil, cover, reduce heat to low, and simmer for 15 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 warm rice. Let cool to room temperature.
03 - With wet hands, shape cooled rice into 12 compact rectangular or oval pieces, about 2 inches long and 3/4 inch thick. Place on a parchment-lined tray.
04 - Refrigerate the rice pieces for 20 minutes to firm up.
05 - In a bowl, combine diced salmon, mayonnaise, sriracha, soy sauce, green onion, sesame oil, and a pinch of salt. Mix gently. Refrigerate until ready to use.
06 - Heat oil in a large nonstick skillet over medium-high heat. Fry rice pieces in batches, 2–3 minutes per side, until golden and crispy. Drain on paper towels.
07 - Top each crispy rice piece with a slice of avocado and a generous spoonful of spicy salmon mixture. Garnish with sesame seeds and microgreens or chives.
08 - Serve immediately with soy sauce on the side.