This form involves rice and nori rolled up with the toppings on a bamboo mat, then sliced into small bite-size rolls. The popular California roll is an inside-out roll with crab meat, avocado and cucumber as the ingredients. ­Rice is the key ingredient in all sushi. Short or medium grain is cooked carefully and blended with a special m­ix of rice vinegar, sugar and salt. The texture and consistency of the rice are both vital to making proper sushi-it should be a bit sticky, not gooey or clumpy.