Prepare your bamboo sushi mat: Cover your bamboo sushi mat with plastic wrap. This will help keep the rice from sticking to it.
Prepare the carrot: Peel the carrot and slice julienne style into thin strips the length of the nori sheet. I like to use the nori sheet as a guide when determining how long to cut each vegetable.
Cut the cucumber: Cut the cucumber into strips that are as long as your nori sheet and about 1/8 inch thick.
Slice the red bell pepper: Cut the red bell pepper into four sections and remove the seeds. Then cut each section into strips around 1/8 inch thick.
Press rice onto nori sheets: Next, place the nori sheet onto the plastic wrap with the shiny side facing down. Then press around 3/4 cup of sushi rice onto about 3/4 of the nori sheet in an even layer. Leave about 1/4 of the nori sheet without rice as this will help seal the roll. Tip: Combine a bowl of water and a splash of rice vinegar and use to wet your hands prior to handling the sushi rice. This will prevent the rice from sticking to your hands.
Cut the avocados: Slice the avocado in half the long way. Remove the seed and cut each half into 8 slices. After the seed is removed, I usually cut the avocado slices straight out of the avocado half and add directly to the roll so the pieces won't brown as quickly. You can also drizzle a little lemon juice over your cut avocado to prevent the avocado from browning in your roll. Each whole avocado should yield around 16 slices. Add the avocado, carrots, bell pepper, and cucumber: Add the avocado slices, carrots, and cucumber sticks horizontally along the nori sheet. In general, I add 2-3 avocado slices, 1-2 cucumber sticks, 1-2 red bell pepper sticks, and a few carrots sticks depending on the size of each ingredient and how everything fits.
Roll the sushi: Wet the part of the nori sheet that does not contain rice. Starting at the side of the nori sheet with rice, use the bamboo sushi mat to fold your roll until it's completely enclosed. Once the nori is making contact with the rice, pull back the sushi mat so it doesn't get caught in the sushi. Still using the sushi mat as your guide, finish rolling until the roll is completely wrapped. Then wrap the sushi mat around the roll and gently press, tightening the roll together.Keep in mind that rolling sushi is an art that may take some practice so don’t get frustrated if it doesn’t look perfect your first time. It will get easier the more you do it. Cut the roll: Using a sharp knife, cut the roll into 8 pieces. I do this by first cutting the roll in half. Then cutting each half in half. Then cutting each fourth in half. Tip: Be sure to clean and wet the edge of your knife before cutting each roll.
Serve and enjoy: I usually serve with soy sauce and wasabi. Sushi rolls are traditionally served with pickled ginger as well.