Rinse the oysters gently in salted water, shaking lightly, then drain off the water.
Peel the ginger and cut into thin strips.
Add kelp to 180ml of water and bring to a boil.
Add the measured amounts of soy sauce, mirin, sake, and the julienned ginger, then bring to a boil.
Add the oysters and simmer over medium-low heat for 10 minutes until done!