Wash the chicken and cut it into small pieces. In a bowl, combine the chicken pieces with the chopped onion, chopped garlic, the heaped tablespoon of honey, 5 tablespoons soy sauce, 2 teaspoons sesame oil, 1 tablespoon olive oil, 4 tablespoons barbecue sauce, and some chili powder. Mix until the chicken is evenly coated, then cover and refrigerate for 30 minutes.
Heat a pan over medium heat. Add the marinated chicken with all the sauce from the bowl to the pan and sear for 10-12 minutes, stirring occasionally. While the chicken is cooking, cut the bell pepper(s) into small strips and add them to the pan after about 5 minutes. Continue cooking until the chicken reaches 74°C (165°F) internal temperature. If the sauce becomes too thick, gradually add water as needed.
Finely chop the spring onion(s) and coriander. Transfer the chicken and peppers to serving plates and sprinkle the chopped spring onion and coriander over the top, then sprinkle with some sesame seeds.