1In a bowl, add chicken, soy sauce, vinegar, crushed red chilli, black pepper powder, salt, chicken powder, and garlic paste. Mix well, cover, and marinate for 25-30 minutes.
2In a frying pan, add cooking oil and marinated chicken. Mix well and cook on medium flame for 6-8 minutes, then cook on high flame until it dries up.
3Add capsicum, onion, and tomatoes; mix well and sauté for a minute. Set aside.
4In a wok, add cooking oil, garlic, and ginger. Mix well.
5Add tomato ketchup and mix well.
6Add chilli sauce, soy sauce, vinegar, red chilli powder, black pepper powder, salt, white pepper powder, and sugar. Mix well and cook for 1-2 minutes.
7Add water and chicken stock cube; mix well and bring to a boil.
8In a bowl, add cornflour and water and whisk well.
9Add the dissolved cornflour mixture to the wok, mix well, and cook until it thickens.
10Add the cooked chicken with vegetables and mix gently.