Place a nori sheet lengthwise on a bamboo rolling mat, shiny-side down. Position the sheet about 1-inch from the edge of the mat closest to you and leave some of the bamboo mat exposed on either side of the nori sheet. Wet your hands in cool water and take a handful of sushi rice. Place the rice in the center of the nori and use your fingers to spread the rice evenly over the nori. Be sure to leave a 3/4-inch strip of nori uncovered on the far side. Place tuna strips and some julienne vegetable

Rinse the rice in cold water while stirring briskly to remove any dirt. Drain the rice completely. Place the rice and the 6 cups of water in a medium sized saucepan and cover it with a tight fitting lid. Bring the water to a boil over medium heat. Allow the water to boil for 3 minutes and then reduce the heat to low and continue cooking 15 minutes without removing the lid. Remove the rice from the heat and remove the lid (the water should no longer be visible). Turn the rice out evenly on a well