2tablespoonsChinese black vinegar, or malt vinegar
2teaspoonstapioca, corn or potato starch
2 tablespoonschopped fresh cilantro
In a wok or large pan, heat the lard or vegetable oil over high heat. When it just barely begins to smoke, add the ginger, garlic and chiles and stir fry for about 30 seconds. Take the pan off the heat and remove the ginger, garlic and chiles with a slotted spoon. Reserve.
Return the pan to the heat and add the mushrooms. Stir fry them to coat in the oil, and when they just begin to release their water, add in the stock, soy sauce, Shaoxing wine, vinegar and sugar, if using. Return the ginger, garlic and chiles to the pot. Mix well and simmer gently for about 20 to 30 minutes. You want the sauce to cook down.
If, when you are ready to eat, the sauce is still thin, mix 2 teaspoons of tapioca, corn or potato starch into about 2 tablespoons of hot water and stir that into the mushrooms. Bring it to a boil and your sauce should thicken and get a pretty sheen on it. Mix in the cilantro and serve at once.