Cook the sushi rice according to package directions.

Prepare the sushi vinegar: Heat rice wine vinegar, sugar, and salt in a small saucepan until dissolved.

Cool the rice slightly and mix in the sushi vinegar.

Peel and seed the cucumber, then slice into thin strips.

Slice the avocado into thin strips.

Slice the smoked salmon into thin slices.

Prepare the spicy mayo: Mix mayonnaise, Sriracha, and finely chopped scallions.

Soften nori sheets briefly over a hot stovetop or open flame.

Place a nori sheet on a bamboo rolling mat.

Spread a thin layer of cooked rice evenly over the nori sheet, leaving about 1 inch uncovered at the top.

Layer cucumber, avocado, and salmon strips across the rice.

Drizzle with spicy scallion mayo.

Using the bamboo mat, tightly roll the sushi.

Cut the roll into even-sized pieces.

Serve with soy sauce, wasabi, and pickled ginger.