Keep the apple pieces in water. Whisk together the soy sauce, vinegar, one tablespoon sesame oil, five-spice powder, honey, ginger, garlic and salt. Marinate the chicken in above mixture for two hours.
Heat the remaining oil in a wok. Add the chicken and toss for two to three minutes. Add the onion, capsicum and apple and continue to toss and cook till the chicken is cooked.
Stir in spring onion and serve hot.