The peanut butter–hoisin sauce is the star of this meal—and it takes only 5 minutes to prepare.
1/2 cup dried wood ear mushrooms 1 teaspoon Chinese black vinegar8 ounces fresh shiitake mushrooms, stemmed and sliced16 store-bought moo shu pancakes or flour tortillas, warmedProcess all peanut butter–hoisin sauce ingredients in a food processor or high-speed blender until smooth, about 2 minutes, stopping to scrape down sides as needed. Store, covered, in refrigerator up to 5 days.Using a cleaver, cut pork tenderloin crosswise into 1/2-inch-thick slices.
Let soak 10 minutes. Drain and rinse mushrooms; set aside. While mushrooms soak, stir together broth, wine, soy sauce, black vinegar, and 1/4 teaspoon white pepper in a small bowl; set aside. Stir together cornstarch and 1 tablespoon water in a separate bowl until combined; set aside.Heat 3 tablespoons oil in a large skillet or wok over high; add shiitake mushrooms. Cook, stirring often, until browned, about 3 minutes. Using a slotted spoon, transfer mushrooms to a bowl.