It’s very simple. Hold a ball of rice in your hand into an oval, then flatten it up and down, and then take a kelp strip that is slightly one-third wider than the rice you just held (cut the large kelp piece yourself ) just make a circle (use some water to make it easier to bond), and then put your favorite ingredients on top. OK. It’s okay to eat and cook for yourself. Even a small sushi restaurant does this, which is also called nigiri sushi.