Combine the broth, wine, sesame oil, sugar, soy sauce, salt, and white pepper in a small bowl and mix well. Place a wok or stir-fry pan over high heat. Add the oil, swirling to coat the sides. Add the garlic and ginger and cook, stirring, until fragrant, about 20 seconds. Pour in the seasoning from the bowl and cook, stirring, until the sugar dissolves. Add the cornstarch mixture and cook until the sauce boils and thickens, about one minute. Store in a covered container in the fridge; the sauce will keep for up to one week.