The set of vegetables widely used for cooking vegetable sushi is rather wide, but the most popular are carrots, asparagus, zucchini and others. Carrots are tricky because they are so hard, but you might want to use mini-carrots, which are a little softer, or start with pre-cut carrot sticks and, depending on their thickness, slice them three or four more times, until they are almost thin enough to be translucent. Asparagus are good because on the contrary they do not need any real slicing, just one cut to make sure they are the same length as the nori (seaweed sheets).
The one thing asparagus does need, however, is a brief steaming. You can do this in a steamer over the stove or in a covered dish with a little water in the microwave on high. In either case, it should take about 2 minutes, depending on the thickness of the asparagus. You can also use spinach to cook vegetable sushi - put washed spinach in a little water and bring to boil, then lower heat and cook for several minutes. Anyway, drain the product for vegetable sushi well and let it cool - it is of great importance as the more water as possible is drained from the spinach the better vegetable sushi will be. This is the to allow the spinach or carrots to cool in a mesh strainer.
Then divide into 10 portions of strips you may not need all the amount of vegetables you have cooked. Then your vegetable sushi needs a good rice addition. Measure 2 cups of vegetable sushi rice (prefer the long and thin grains) into a large bowl.
As in many Asian cuisines, the rice is rinsed. First, by stirring it in cold water, carefully pouring off the cloudy, starch-filled water and repeating-about three times in all. Set in a colander to wash rice until water runs clear for about 30 minutes, drain well. Now it is time to combine rice and 5 cups water in large saucepan, bringing to boil; reduce heat and simmer on the lowest possible heat, cover 20-25 minutes, or until water is absorbed.
The necessary tip on preparing not only vegetable sushi, but any other kind of it - do not stir the rice! Better stick a fork into it to bottom of pan and if no water remains, it's ready. While the rice is draining, and then later, while it is cooking, you can prepare little piles or stations for vegetable sushi assembly. Set out a bowl of water to keep hands moist while spreading rice. If using wasabi, put a few spoonfuls in a bowl for easy access, and cover (and warn kids how spicy it is!). Cut sheets of nori in half, storing in a large zipper bag to keep it moist.
Hold line of ingredients across rice firmly in place with fingertips. Using your thumbs, push up and turn vegetable sushi mat edge nearest you up and over filling, pressing firmly to enclose filling, and lifting the mat while rolling to keep it free from being enclosed in the sushi roll. The art of making vegetable sushi is to get filling ingredients lined up in the center of the roll.
To serve, place vegetable sushi, seam-side down, on cutting surface and cut crosswise into about 8 equal slices or you can follow the Japanese tradition to serve vegetable sushi with miso soup . Do we need to say, that refrigeration will cause vegetable sushi to dry out, so eat it immediately?