In a mixing bowl add the hoisin, soy sauce and 2 tbsp water and mix.
Add the chicken and mix well. Leave to marinate for 20 minutes.
Spray the wok with low calorie cooking spray, place over a medium to high heat and add the chicken, saving some of the marinade for later.
Cook chicken for 5 minutes then move to one side and add all of the vegetables, garlic and ginger.
Add the remainder of the marinade and continue cooking for 10-15 minutes, until chicken is cooked, the juices run clear and there is no pinkness, and the vegetables have softened.
While the chicken is cooking, place all of the ingredients for the Yum Yum sauce into a mixing bowl and mix well.
Serve the chicken and vegetables drizzled with the Yum Yum sauce.