Marinate the chicken with the soy sauce, Shaoxing wine, potato starch and white pepper. Let this rest and prepare all of the other ingredients.
Make the sauce, by mixing the chicken stock, oyster sauce, potato starch and sesame oil together in a small bowl.
Heat a large skillet or wok over medium high heat until until very hot. Add the oil and then immediately add the cashews. Stir-fry until the cashews are a deep golden brown and then transfer them to a bowl, leaving as much oil in the pan as you can.
Add garlic and ginger and give them a swirl in the oil, and then add the marinated chicken in a single layer. Let this fry undisturbed until the chicken is browned on one side.
Start stir-frying the chicken until cooked on all side (it doesn't need to be cooked all the way through at this point).
Add the vegetables and continue stir-frying until they're cooked through.
Give the sauce a mix to incorporate the settled potato starch and then pour it over the cashew chicken. It's done when the sauce comes to a boil and thickens. Plate and garnish with the scallions.