Slice cucumber, cut to about the size of kani/surimi
Thinly slice avocado
In a small bowl, mix 1-2 Tbsp vinegar with a cup of water, keep this at the wrapping site so that you could wet your finger when spreading sushi rice.
Lay the bamboo sushi mat onto a flat surface, wrap a piece of plastic food wrap over it. This is to prevent the sushi rice from sticking to your mat.
Place a Nori sheet onto wrapped bamboo mat(texture side up). I only use about 3/4 of the nori sheet, the more you use the bigger the final roll is, so adjust this to your desire.
Wet your finger/hand with the water-vinegar solution, then make a couple sushi rice ball and place them on the nori.
Spreading the rice out to cover the whole nori (keep your hand wet with wate-vinegar to avoid rice sticking to your finger).
If need, add some rice, so that the rice layer is evenly distribute. Do not mush the rice thought, just press gently.
Turn the nori over (rice layer facing down)
Put kani, cucumber and avocado on the nori
Roll with the bamboo rolling mat, start by using the nearest bamboo mat edge fold over the cover the filling. Then, hold tightly and keep the mat moving to roll until the end.
Put pressure on all over the roll outside mat, now carefully open the mat, and there's your roll.
Leave it be for about 3-5 minutes before cutting to serve or continue for a fun Dragon roll extension below.