This is one of the basic maki rolls made with raw red tuna. Practice with this one first and the others will be much easier to roll.
2 strips red tuna cut about 3-1/2 inches long and 3/8 inch square
About 1/2 cup sushi rice
1 sheet nori
Lay the nori sheet on a flat surface or a bamboo mat. Use some plastic wrap over the bamboo mat to keep the rice from sticking on it if desired. Cover the bottom portion of the nori with rice no thicker than 1/4 inch. Leave about 1 inch of the nori uncovered at the top. Wet your hands continually while doing this or the rice will stick to your fingers. Lay the stips of tuna on top of the rice covered nori about 1-1/2 inch from the bottom. Now roll the bottom of the nori over the tuna and all the way to the top. Press the roll firmly together and slice into segments 1 inch long with a wet, sharp knife. You must wet the knife or the rice will stick and tear the nori.
Notes: You may also use bits and pieces leftover from slicing maguro nigiri for these rolls. Also, you may use other types of fish for this simple roll. If you use salmon, it would be called Sake Maki. Albacore, yellowtail or halibut may also be used.