Wash spinach thoroughly without breaking off any stems or leaves.
Bring water to a full boil then add salt, then the spinach. Blanch until it starts to wilt (no more than 20 seconds).
Drain and rinse under tap water to cool. Then squeeze out any excess water.
Prepare the dressing
In a small bowl, mix ginger paste with black rice vinegar, light soy sauce, sesame oil, and sugar.
Assemble the dish
Cut the blanched spinach crosswise into sections. Place it on a plate. Pour the dressing over then garnish with toasted sesame seeds.
Notes
1, You may also use regular spinach. In this case, decrease the blanching time to just a few seconds, as it wilts faster than savoy spinach.2. Use a fine grater or a pestle and mortar to make fresh ginger paste. Alternatively, you can use shop-bought, jarred ginger paste.