Trim the heads and add the fish to a pot
Add 3 cups of water, vinegar, and soy sauce, then top with green onions and pork fat; cover with a lid
Add salt to taste; bring to a boil and let simmer for about 20 minutes or until 10% done
Add brown sugar and lard or cooking oil; simmer for about 15 minutes
Add coconut milk and cook for another 20 minutes or until done
Prepare a double boiler by placing a pot with water on top of another pot with a tight-fitting lid; to make cleaning the same as cooking in an oven for easier cleanup when you are finished
After cooking, remove the whole fish from the broth, let it cool and remove the bones
Cut it into serving pieces and pour the broth over the fish
Serve hot with steamed rice