Rinse 250 grams of sushi rice in cold water until the water runs clear. Drain and let it sit for 30 minutes.
In a saucepan, combine the rice with 330 ml of water. Bring to a boil, then reduce the heat to low and cover. Cook for 15 minutes, then remove from heat and let it sit, covered, for another 10 minutes.
In a small saucepan, combine 50 ml rice vinegar, 15 grams of sugar, and 5 grams of salt. Heat until the sugar dissolves, then let it cool.
Transfer the cooked rice to a large bowl and gently fold in the vinegar mixture. Let the rice cool to room temperature.
Prepare your desired fillings, such as thinly sliced raw fish, cooked shrimp, cucumber, avocado, or paneer.
Place a sheet of nori (seaweed) on a bamboo sushi mat. Spread a thin layer of rice on the nori, leaving a small border at the top and bottom.
Arrange your chosen fillings in a line along the bottom third of the rice.
Using the bamboo mat, roll the sushi tightly, applying gentle pressure to ensure it stays together. Wet the top border of the nori with a little water to seal the roll.
Using a sharp knife, slice the sushi roll into bite-sized pieces. Serve with soy sauce, wasabi, and pickled ginger.