Stir fry Potato with Chicken and Mushrooms

Saw a similar dish on TV a week ago, so Randal request to cook this, I didn't note the ingredients so just cook my own version.

Ingredients:
300g Chicken - chopped into small piece ( I use chicken mid-joint wings)
2 potatoes - cut into cube
5 mushrooms - soaked
2 stalks of spring onion- cut into long strips
3 shallot- slice thinly
1tbsp chop garlic

chicken marinate:
pepper
1 tsp light soy sauce
a little sesame oil

sauce:
1-2 tbsp oyster sauce
1 tsp dark soy sauce
1 tsp light soy sauce
1 tbsp rice wine
1 tbsp sugar
water

Method:
1. Rinse and marinade the chicken for at least 2 hours in the fidge.

2. Heat wok pan fry chicken till slightly brown, dish and set aside, then pan fry potatoes till brown too, dish aside.

3. Add a little oil, fry shallots and garlic till fragrant, add the chicken, potato and mushrooms, stir fry a while, add in the sauce ingredients, add water till it covers at least 3/4 of the dish, simmer at low fire till potato is soft and chicken is fully cooked, stir the content in between so that its well cooked by the sauce. By then the sauce should be cooked till less than half.

4. Add in spring onion stir fry a while. Dish and serve.