Mackerel in soy sauce

Ingredients

Steps

Make an X shape cut in the middle of the mackerel to prevent the skin from tearing.
Slice the ginger.
In a pot add the soy sauce, the sake, the sugar, the ginger and the water. 
Bring to simmer.
Put the fish in the pot.
Cover the pot and let it simmer for 5 minutes.
Turn off the heat and leave the fish in it for 20 minutes.