Step 1

Put the dried mushrooms in a large bowl, and pour the hot water over the mushrooms, making sure they are submerged. Let the mushrooms soak for at least an hour.

Step 2

Then add the mushrooms and the water the mushrooms were soaking in to a blender. Blend on high until the mushrooms and water have made a very smooth mixture.

Step 3

Pour the mushroom mixture into a small sauce pan. Then add the soy sauce or tamari, the agave, the miso, and the ginger to the pan, whisk to combine. Heat the pan on medium, bring to a simmer, reduce heat to low.

Step 4

Simmer for about 10 minutes to cook the mushroom mixture and thicken slightly.

Step 5

Now, in a small bowl, whisk together the cornstarch and water until the cornstarch has dissolved.

Step 6

Whisk the cornstarch into the pan.

Step 7

Then continue to simmer for about 5 minutes or until the oyster sauce is nice and thick.

Step 8

Let cool and then keep in an air tight container and refrigerated. It will last for several weeks.