Season the rice with rice vinegar, mix, and set aside.
Prepare other ingredients.
Wrap your bamboo sushi roller with cling film.
Wet your hands then spread out the rice in nori sheets then spread sesame seeds on top.
Turn it upside down and place it on the bottom of the bamboo roller.
Place cucumber and carrots on top of the nori, then roll and tuck. Make sure that all fillings are compressed.
Roll and tuck once more to lock the sushi. If fillings fall out, put the roll on the edge of the bamboo roller, roll and tuck it all inside.
Place thinly sliced avocado on top of the roll.
Put cling film on top of the roll, then the bamboo roller, and use those to wrap and tuck the avocado in the roll.
Once avocados are wrapped and tucked, remove bamboo roller and keep cling film, then slice into 6-8 pieces.
Remove cling film and plate the sushi rolls.
Dip in soy sauce and enjoy!