Finely chop onions and mince chillies. Beat curds and dilute it with one more cup of water. Add salt to this. Heat a heavy based deep frying pan with oil. Add the seasonings and then chillies with onion. Fry 2 minutes and pour prepared butter milk. When it starts boiling reduce flame and put rice flour as a heap in the centre of the butter milk. Insert a flat ladddle in the centre and cover with a lid on top and cook for 5 to 7 minutes. Remove from fire and quickly mix with that inserted laddle. Put back on fire, adding more oil if necessary. Stir constantly for another few minutes. When it doesn't stick to hand if touched with wet hands, it is ready. Remove from fire and add cut coriander, curry leaves. Pour on a greased plate and spread evenly to 1 inch thickness. Cut into pieces before serving. Serve with pickle.