In a bowl, mix together the first 6 ingredients from the above list. Add salt and mix well. Heat 1/4 cup vegetable oil in a pan and shallow fry the chicken pieces on both sides. Cover and cook till chicken pieces are completely cooked.
In another saucepan or wok, heat 5 to 6 tablespoons of vegetable oil. Add chopped garlic and ginger till they slightly change color. Then add finely chopped onion and fry till just soft, followed by capsicum and roughly chopped onion. Fry for a few seconds on high heat.
Now add red chili sauce, tomato sauce, and soy sauce. Give everything a quick stir on high heat, also add sugar, vinegar, and cooked chicken pieces. Stir gently but keep the flame high.
Finally add salt if needed, green chilies, and chopped spring onion. Stir for 30 seconds more on high heat and the chili chicken is now ready.
Serve hot with fried rice or noodles.