In a microwave-safe bowl, combine the spinach leaves, water, dark sesame oil, and a pinch of salt.
Cover and microwave on high for 30 seconds until just wilted.
Carefully remove the hot spinach from the bowl and squeeze it firmly to remove as much excess liquid as possible. This step is crucial for preventing soggy nigiri.
Moisten your hands with a little water to prevent sticking. Take about 2 tablespoons (30 ml / 1 fl oz) of prepared sushi rice and gently squeeze and shape it in your palm to form a small, rectangular bed.
Repeat until you have 12 rice beds.
Drape a portion of the wilted spinach neatly over each bed of rice, pressing down gently so it adheres.
Sprinkle the finished nigiri with black sesame seeds for a beautiful contrast and nutty flavor.
Serve immediately and enjoy!
When cooking, try to keep the spinach leaves oriented in the same direction. This makes them easier to drape elegantly over the rice.
Keep a small bowl of water nearby to dip your fingertips in while shaping the rice. This tezu water prevents the sticky rice from clinging to your hands.
Don't over-squeeze the rice! A gentle but firm pressure is all you need to form the nigiri bed. Compacting it too much will result in dense, hard rice.
