Heat oil in a sauce pan and fry chopped garlic till the raw smell disappears and color changes slightly.
Add finely chopped boneless chicken pieces along with salt and pepper powder and fry till chicken is well cooked.
Now add soya sauce, red chili sauce, tomato puree, and tomato sauce. Lower the heat, add 4 cups chicken stock and cook on low flame for 2 minutes.
Add brown sugar, chili flakes, and vinegar.
To thicken the soup add cornflour mixture little by little till you get the consistency of your choice.
You can add beaten egg white in a thin stream and keep stirring as you add. Adding egg is optional, you can prepare soup even without it.
Garnish with lots of green chopped spring onion and serve hot.