Place the chicken drumettes in a shallow bowl. Add the five-spice powder, soy sauce, rice wine, oyster sauce and chili flakes. Mix well. Cover and keep in the fridge for a couple of hours.
Heat the cooking oil in a wok or frying pan.
Place the starch in a resealable bag. Drop in the chicken drumettes. Seal and shake well.
Fry in hot oil over medium heat, in batches of six to eight, for about three minutes. Turn up the heat to high and fry for another minute. Transfer to a plate lined with paper towels.
When all the chicken drumettes have been fried, take a clean frying pan and pour in the hoisin sauce. Heat gently, spreading the sauce over the entire bottom of the pan. Add the cooked chicken drumettes. Sprinkle the toasted sesame seeds over them. Toss to coat each chicken piece with hoisin sauce and sesame seeds. When all of the sauce has been absorbed, transfer the chicken drumettes to a serving plate and serve at once.