Start by preparing the sushi rice according to the package instructions. While the rice is cooking, you can begin preparing the other ingredients.

Cut the raw salmon into thin slices. You can also dice the avocado and cucumber, if using.

Once the rice is finished cooking, let it cool for a few minutes. Then, place a sheet of nori on a flat surface, shiny side down.

Spread a thin layer of sushi rice over the nori, leaving a 1-inch border at the top.

Arrange the salmon slices, avocado, and cucumber (if using) in a line across the center of the rice.

Spread a small amount of mayonnaise over the top of the salmon and vegetables.

Sprinkle tempura flakes over the mayonnaise, and then drizzle with chili flakes or Sriracha sauce for a spicy kick.

To roll the sushi, use your fingers to lift the edge of the nori closest to you and gently roll it over the filling. As you roll, use your fingers to tuck the filling in and keep the roll tight.

When you reach the end of the nori, dampen the 1-inch border with a little water to help seal the roll. Then, gently press the seam to seal it.

Repeat the process with the remaining ingredients to make additional rolls.

To serve, cut the rolls into bite-sized pieces using a sharp knife. You can serve the rolls with soy sauce, pickled ginger, and wasabi for dipping, if desired.