Combine all of the Hoisin sauce ingredients in a jug and set aside.
Mist a wok with low calorie cooking spray and heat. When the wok is hot add in the onions and mushrooms. Fry until the onion begins to colour.
Add in the chicken and drizzle a 1/4 of the sauce into the pan. Make sure all the chicken is coated and continue to cook until the chicken is coloured.
Before serving stir through the spring onion and enjoy!