Making homemade nigiri isn't as difficult as you'd think! With good Japanese rice and high-quality fish, you have (almost) everything you need for amazing nigiri.
2cupsuncooked Japanese short grain rice
1/2lb. fresh, uncooked sushi grade tuna
1/2lb. fresh, uncooked sushi grade salmon
soy sauce, wasabi paste, and pickled ginger for garnish
Cook rice according to package instructions, preferably in a rice cooker. While rice is cooking whisk together the rice vinegar, sugar, and salt until the sugar and salt are completely dissolved. Once rice is done cooking, place the rice in a large bowl, add vinegar mixture to hot rice, and toss. Set aside to let rice slightly cool.
While the rice is cooling, cut the fish. Cut against the grain of the fish to form pieces that are roughly 3" long, 1" wide, and 1/4" thick. Set aside.
Form mounds of rice. Fill a small bowl with water, wet your hands, and place a small mound of rice that comfortably fits in your left hand (about 3/4 the size of your palm) when cupped. Keeping the left hand cupped, press down on the top of the mound with the long/inside surfaces of your right hand's pointer and middle fingers (together), gently forming the rice into a slightly more compact, structured mound. Don't squeeze the rice too tight. Set each mound aside and repeat until all rice has been used.
Combine the rice and fish to form pieces of nigiri. With your left palm facing up, lay one piece of fish horizontally across the base of your fingers, and place one prepared mound of rice directly on top. Repeat the same motion as you did when forming the rice mound-- gently cupping your left hand and pressing down with the long side of your right hand's pointer and middle fingers, forming rice and fish together. Place formed pieces of nigiri on a large plate, and serve immediately with soy sauce, wasabi paste, and pickled ginger.
1 Rice Cooker, optional but highly recommended for best results