Soak the chillies in warm water for 10 minutes and drain. Grind them with garlic, salt, sugar and vinegar into a fine paste. Keep aside. (This is a rather spicy paste. So use only as much as you require.)
Marinate the chicken with egg and corn flour. Add a bit of salt as well. Keep aside for 10 minutes.
Deep Fried the chicken pieces in hot oil till golden brown. Drain onto an absorbent paper.
Heat oil in a pan. Saute the spring onion for 30 seconds. Add the chilli-garlic paste followed by ketchup and soy sauce. Stir well.
Add the chicken stock and let it boil. Add the fried chicken pieces, peanuts and mix well. If the gravy is too watery, add the corn flour mixed with water into the gravy when it starts to boil.
Slowly the gravy will turn thick. Switch off the heat. Garnish with chopped spring onions and serve hot.