Wash and clean the chicken thoroughly. Soak it in water with 1 tbsp lemon juice for 5 minutes. Drain and keep aside.
Make a marinate using the above ingredients and apply it on the chicken pieces. Keep it in the refrigerator for one hour(its very important).
Heat oil in large frying pan and place the chicken pieces in oil and fry in medium flame, till all sides are fried properly.
Remove the fried chicken pieces from oil and keep aside.
Add sliced onions to the same oil and saute well.
Add slit green chillies, tomatoes, curry leaves and continue sauteing until the tomatoes have been cooked.
When the onions begin to brown, add the fried chicken pieces and mix well.
Add tomato ketchup and soy sauce along with required salt. Cover and cook in low flame for around 5 minutes so that the chicken pieces are coated well with the thick masala.
:- serve with rice or roti. If you don`t like the taste of sauce just add one more tomato instead.