Soak dried mushrooms in hot water. The special taste of dried mushrooms comes from the mushroom essence and guanylic acid contained in them, especially guanylic acid, and its umami flavor intensity is dozens of times that of ordinary monosodium glutamate. When soaking dried mushrooms, it is recommended to use hot water at about 20-35℃, which will not only make mushrooms absorb water more easily, soften and swell, but also fully decompose guanylic acid and give off fresh flavor. In addition, the soaking time should not be too long. When the mushroom covers are all soft, they should be immediately picked up and drained.