Fill a wok or other large skillet halfway with water (bring to a boil). Place a grate above it, place a small frying pan on it (to make a steam bath).
In a bowl, beat coconut milk with eggs, sauces, and sugar, stir well.
Put the fish in the pan, which is located above the steam bath, pour the coconut mixture. Cover the frying pan with a lid, steam until the fish is fully cooked.