Creating your own Spicy Cucumber Sushi Rolls is simple if you follow these steps:

1. Prepare Sushi Rice: Rinse the sushi rice under cold water until the water runs clear. Drain well.
2. Cook Rice: In a saucepan, combine the rinsed rice and water. Bring to a boil, then reduce heat, cover, and simmer for 18-20 minutes until the water is absorbed. Remove from heat and let it sit for 10 minutes.
3. Season Rice: In a small bowl, mix rice vinegar, sesame oil, and salt. Gently fold this mixture into the cooked rice. Allow it to cool slightly.
4. Prepare Spicy Sauce: In another bowl, combine mayonnaise and Sriracha sauce. Adjust the level of spiciness based on your preference.
5. Lay Nori: Place a sheet of nori on a bamboo sushi mat or a clean surface.
6. Add Rice: With wet hands, spread a thin layer of sushi rice over the nori, leaving a 1-inch border at the top.
7. Add Fillings: In the center, layer julienned cucumber and avocado slices (if using). Drizzle with the spicy sauce.
8. Roll Sushi: Using the mat, carefully roll the sushi away from you, applying gentle pressure. Seal the edge with a little water.
9. Slice Rolls: Using a sharp knife, slice the roll into bite-sized pieces. Wipe the knife with a damp cloth between cuts for clean slices.
10. Garnish: Sprinkle sesame seeds over the rolls for added flavor and texture.

These steps will guide you in creating Spicy Cucumber Sushi Rolls that are not only delicious but also visually stunning.