Mix the soy sauce with the water, then blend in the cornstarch. Stir in the wine, sugar, ginger, red pepper and salt.
Preheat a wok or large fry pan over high head. Add 2 teaspoons of vegetable oil. Stir-fry the green peppers and onions for 2 minutes and remove. Add the walnuts and stir fry for 1-2 minutes or until golden brown. Remove.
Add the rest of the oil and stir fry the chicken. (You may need to add more oil or some stock if the pan is dry.)
Once the chicken is no longer pink, add the soy sauce mixture. Then stir in the vegetables and walnuts, cover and cook until heated through.