Cut 2 scallions into 2in / 5cm lengths and julienne them. Roughly chop 1 small bunch of cilantro. Put a third of the scallions, cilantro, and 2 tablespoons of julienned ginger on a small plate.
Mix 1½ tablespoons of light soy sauce, ⅛ teaspoon of salt, ⅛ teaspoon of sugar, and 2 tablespoons of hot water.
Put 285g of sea bass fillet on a heatproof plate. Steam, covered, over boiling water for 7-10 minutes, until a butter knife slides easily through the thickest part.
Turn off the heat, drain the liquid from the plate, and scatter the reserved aromatics over the fish.
Heat 2 tablespoons of vegetable oil in a small pan and fry the remaining ginger for 1 minute. Add the remaining scallions, whites first, then the cilantro.
Add the soy mixture and let it bubble for about 30 seconds, until the scallions barely wilt. Pour over the fish.
