Take the duck meat off the bones and cut off the fat. Chop the meat finely. Discard the fat and half the skin.

Combine duck bones, reserved skin, onion, water, ginger, star anise and chili in a large pot. Bring the mixture to a boil, then simmer covered for an hour.

Put the mushrooms in a heatproof bowl. Cover them with boiling water and stand for 20 minutes. Drain off the water.

Meanwhile combine the duck meat with the green onion and hoisin sauce in a bowl. Place a rounded teaspoon of this mixture in the center of each dumpling wrapper. Brush the edge with egg white, gather the edges together and finally twist to seal.

Strain the duck stock into a clean pot and skim the fat off the surface. Add the prepared mushrooms to the stock with the cabbage, broccoli, five-spice and soy sauce.

Add the wontons to the soup in batches. Simmer uncovered for about 2 minutes or until hot. Add the garlic chives and season to taste with salt and pepper.

Divide the wontons between 6 serving bowls, and then pour the soup over them. This is one of the best wonton soup recipes if you want to seriously impress your dinner guests and, of course, if you are partial to delicious duck recipes. There are other wonton soup recipes you can look at too.