Cucumber-Avocado Cauliflower Rice Sushi

Place a sheet of nori shiny-side down on a bamboo rolling mat. Spread 1/2 cup cauliflower rice over half the sheet, pressing along the edges. Arrange 1/8 of the avocado slices and 1/8 of the cucumber matchsticks about 1 inch from the bottom of the rice. Roll up tightly, leaving the last inch of the nori exposed. Dip your fingertips into a bowl of water and wet the exposed nori, then finish rolling it closed. Roll the bamboo mat over the maki roll to form an even cylinder. Cut into 8 pieces. Drizzle with 1 tablespoon of the Sriracha mayo. Repeat with the remaining ingredients.