Steamed Chicken with Mushroom in Oyster Sauce (鮮菇蠔油蒸雞)

Ingredients:

5 white mushrooms
5 shiitake mushrooms
4 – 5 boneless chicken legs
1 egg white
2 tbsp ginger slices
4 green onion
2 tbsp oyster sauce
1 tsp cooking wine
1 tsp cornstarch
1 tsp sesame oil