Rinse sushi rice under cold water until clear, then cook according to package instructions, cool to room temperature, and refrigerate for 30 minutes.

In a medium bowl, dice salmon and mix with mayonnaise and sriracha until well coated.

Use a square mold to shape chilled rice into 2-inch squares, pressing down to compact.

Heat oil in a skillet, fry rice squares for 3–4 minutes on each side until golden brown.

Top rice squares with salmon mixture, avocado slices, and jalapeño if desired.

Serve immediately for best texture or chill and serve later.