Prepare the cucumbers: peel the cucumber and cut in half. Cut the cucumber around as a thin peel (see top picture). It should be noted that this peel can be used as the wrapper instead of nori (seaweed wrapper). For filler, however, flatten, fold, and stack the peel and cut in half. Re-stack and chop into fine strips (see middle picture). Set aside.
Prepare The Avocado
Peel and pit the avocado.
You can rub it with lemon juice to help preserve it. Cut the avocado in
half and then into 1/4 inch thick strips.
Press and Push, Press and Push
Place nori on your
preparation surface with the long side facing you (see bottom
picture). Dip your fingers a couple of times in the water bowl, rub your
hands together and give a little clap to remove excess. Grab some rice and
form into a ball just a bit larger than a baseball. Place the rice ball in
the center of the nori and re-moisten hands. Press and push the rice,
spreading it with the thumbs and fingers to cover the nori. Don't want to
work it too much. It is good to have little hills and valleys. Sprinkle
sesame seeds on top. Continue to moisten and clap hands. Flip the nori
over so that the nori is now on the top.
Now for the filling. Helpful hint is that whatever filling you are using, leave a bit of room on the sides so the filling doesn't get squeezed out. Put the cucumber strips in to piles along the center line and short side of the nori. There should be about 6 strips in each pile. Lay 3 avocado slices along the top of the cucumber pieces. Spread crab meat over the the top of the avocados (see top picture).
Roll the side nearest over the central ingredients and finish the roll such that the "seam" is on the bottom. Helpful hint is to "hold and tuck" the ingredients with the fingers while using the thumbs to roll. Tuck and roll, tuck and roll.
Tear a sheet of plastic wrap about the same size as your makisu. Place plastic wrap over the roll so that approximately 1 inch extends onto the counter and the longer end closest to you. Another traditional way to form the sushi is to use a clean cloth dinner napkin. The napkin should be wet and then wrung out. Place the mat over the roll and plastic wrap. With both hands, press lightly on the sides to firm up the roll (see middle picture). There is no need to apply pressure to the top of the roll or to slide your hands along the mat. Just spread your fingers slightly and with one light squeeze, the roll is ready. Slide the mat to one side and then the other to tap the two ends of the roll to make it neat.
You are ready to cut the roll into 8 pieces. The knife must be very sharp. Place the tip of the knife into your water bowl and with the handle down, tap the end of the handle on the table such that the water flows over the entire blade. This will insure that the rice does not stick to the knife. Remove the makisu and with the plastic wrap still on, cut the roll in half (see bottom picture). Cut each of the halves in half and again and one more time so that you have 8 pieces. Place the makisu over the roll again and press lightly to re-form the roll. Remove the mat and the plastic wrap and... Moisten hands once more to move the rolls to a serving plate. Mix wasabi and soy sauce as a dipping condiment and serve with a side of ginger.