Cook chicken in the oven or air fryer for ~25mins, the inside should be 165°, chop into chunks and set aside.
Chop onion into rough pieces and lightly fry for 3mins with the mushrooms, set aside.
Cook noodles following the package’s instructions, drain and add Sesame oil and stir in to prevent sticking.
Add the cooked noodles to a frying pan on medium heat, and lightly crisp the noodles for a couple of minutes on each side.
Add the bean sprouts to the pan and put the noodles on top, steaming the bean sprouts and trapping in the heat, cook for 4mins.
Whilst cooking combine the two soy sauces, sugar, water, and oyster sauce in a bowl, stir well then add to the pan with the chopped chicken.
Stir in the sauce until everything is covered and leave for a couple minutes for everything to be heated through.
Dish up and enjoy ~