Prepare Ingredients: Slice ginger and garlic. Cut dried Mandarin peels into small pieces and soak them in water.
Make the Sauce: Combine oyster sauce, light soy sauce, dark soy sauce, cooking wine, white pepper, brown sugar, salt, and water in a bowl.
Blanch Drumsticks: Pierce the thickest part of each drumstick with a small knife, then blanch them and set aside.
Stir-fry Aromatics: With some oil, stir-fry the ginger, garlic, and dried Mandarin peel.
Simmer with Sauce: Add water and let it simmer covered. Then add half of the sauce, followed by the chicken, and then the rest of the sauce on top. Simmer covered.
Reduce Sauce and Serve: Flip the drumsticks, then turn up the heat to reduce the sauce, basting constantly. Plate the drumsticks and serve with some of the delicious sauce.