Rinse the rice in running cold water 15-17 times until the water becomes clear. Prepare the sushi filling in advance. Thinly slice the fish, cut the avocado into strips, place the cheese in a bag and cut off the end. Wrap the mat on all sides with cling film and grease with a thin layer of vegetable oil. Cut the nori sheet in half.
Cook the rice. The proportions of rice and water are 1:1. Prepare the rice dressing by whisking the vinegar, salt and sugar until completely dissolved. Add the dressing to the rice and stir gently. Place the mat on a flat surface with the rough side facing up. Spread the rice with your hands, occasionally wetting your hands in cold water.
From above, retreat about 2 centimeters, from below, on the contrary, go beyond the sheet. Carefully turn the rice side down. Place avocado and cheese on a sheet of nori. Roll, lightly pressing the roll with a mat. Spread thinly sliced fish over the roll and cut off the edges. Cut the roll with a sharp knife, wetting it with cold water each time.
Serve sushi on individual wooden boards or on one shared board or plate. Take a small bowl and pour soy sauce into it. For connoisseurs of Japanese cuisine, serve special bamboo chopsticks. Place pickled ginger and wasabi sauce next to the sushi if desired.