Grind together red chillies, garlic and vineger.
Marinate the chicken pieces with the above for 30 mins.
Steam this on low fire, till half done.
Heat oil in a pan.
Fry onions, till brown and keep aside.
Heat up the remaining oil.
Fry chicken pieces, till done.
Add chopped tomatoes and cook, till it becomes soft.
Add cooked or excess water of chicken and boil well.
When the gravy becomes half thick, add the previously fried onions and remove from flame.
:- Serve hot with fried rice.