Add 1.5 tablespoons of furikake to a quart of water.
Furikake is a mix of seaweed flakes and sesame seeds. A few brands will add fish, so check the label carefully! Mishima brand's Nori Komi Furikake is a vegan version.
Thinly slice 8 oz of shiitake mushrooms. No other mushroom will do! Shiitake has a flavor that is at once rich, buttery, and meaty. It puts other mushrooms to shame.
Add the mushrooms to the furikake and water. Raise this mixture to a boil, then lower the temperature to simmer for at least 20 minutes.
The completed shiitake no dashi is the resulting brown liquid. Siphon the liquid and set the solid mushrooms aside to re-use in another recipe (as they are both delicious and expensive).
This liquid can be frozen for use indefinitely.