Stir fry chicken and button mushroom

One of our favourite comfort dishes since childhood:

Marinate chicken with light soy sauce and tapioca flour. 

Fry ginger in sesame oil with cooking oil. 

Add chicken. Stir fry with ginger till meat turns light brown. Add oyster sauce, light soy sauce, sugar little and dark soy sauce (for colouring). Stir fry till the sauce coated the meat. Add water and button mushroom, simmer till cook.  打芡。Add chinese cooking wine. 

Spring onion just before dish out.