If you have leftover fish that has already been cooked, you can crumble it up and marinate it. The same recipe applies to a specially cooked fish!
I propose the following sauce, the amount of which will depend on the fish available.
Place one tablespoon of olive oil, the juice of one lime in a blender. Grate lemongrass and a small piece of ginger. Mix and pour over the fish.
When serving, add salt, pepper and herbs (cilantro).