Green Beans with Mushroom XO Sauce

Name: Green Beans with Mushroom XO Sauce
Ingredients: 2 pounds green beans, divided; Kosher salt; 5 tablespoons mushroom soy sauce or 3 tablespoons regular soy sauce; 2 tablespoons black (Chinkiang) vinegar; 2 tablespoons unseasoned rice vinegar; 1 tablespoon sugar; 2 tablespoons vegetable oil, divided; 4 ounces king trumpet or maitake mushrooms, caps sliced, stalks coarsely chopped; 4 ounces shiitake mushrooms, sliced; ¼ cup brandy; 1 shallot, very thinly sliced; 1 Fresno chile, thinly sliced; 2 garlic cloves, thinly sliced; 2 tablespoons small dried shrimp or a splash of fish sauce; 4 scallions, green parts only, thinly sliced on a diagonal, divided; 1 tablespoon chili oil; Black (Chinkiang) vinegar is an aged vinegar made from glutinous rice and malt. It can be found at Asian markets.