Slice the beef along the grain into thin slices that are about 1/2” (4 mm) thick and 2” (5 cm) long. Then further slice it into strips along the grain. Transfer to a medium-sized bowl. Add the doubanjiang, Shaoxing wine, dark soy sauce, and white pepper. Mix until all the liquid is absorbed. Add the cornstarch and mix well to coat. Then add the oil and mix again. Let marinate while preparing the other ingredients.