All you need to use is a microwave. You can make it in 5 minutes! No need for a cutting board or a knife.
I came up with a butter version of the delicious simmered king oyster mushrooms (Recipe ID: 1308328).
It's ok to pour the seasoning ingredients (sauce) on top of the king oyster mushrooms. The mushrooms should absorb the flavour, but it's better to stir lightly at the end just in case.
Enjoy Japanese food around the world.