Braised chicken with yam

Ingredients

• 1/2 chicken, chopped
• 400 g baby yam
• 2 slices ginger
• 2 tbsp oyster sauce
• 1 tbsp sesame oil
• 1 cup water
• 1 1/2 tbsp light soya sauce
• 2 tbsp chinese cooking wine
• 1 stalk spring onion, chopped
• cornstarch water