Separately in a clean pan on medium heat, add oil, ginger, garlic, onions (only the white part), chillies and let it cook until aromatic, add the hot water, soy sauce mixture and let it come to a boil, check for seasoning, pour over the fish, place fish in the hot steamer, turn the stovetop heat to medium and let it cook for around 8-10 minutes or until the fish cooked.