Rinse the sushi rice under cold water until the water runs clear.

In a medium pot, combine the rinsed rice and water. Bring it to a boil over medium heat, then reduce the heat to low, cover, and simmer for about 20 minutes.

Once the rice is tender, remove it from the heat and let it cool.

In a small saucepan, mix together the rice vinegar, sugar, and salt over low heat until dissolved.

Once the rice has cooled a bit, gently fold in the vinegar mixture. Allow it to cool to room temperature.

Place a sheet of nori on your bamboo sushi mat, shiny side down.

With wet hands, spread about ¾ cup of sushi rice evenly over the nori, leaving a 1-inch border at the top.

Arrange your fillings—cucumber, carrot, avocado, and bell pepper—horizontally across the center of the rice.

Roll the sushi away from you, using the mat to keep a tight roll.

Use a sharp, wet knife to slice the roll into bite-sized pieces.

Display your sushi artfully on a platter, sprinkling sesame seeds for decoration.