Chop spring onions into small pieces.
Soak rice and toor dal in water for about 30 mins.
Heat a little oil and fry coriander seeds, red chillies.
Grind them with coconut, tamarind, toor dal, rice without adding too much water. The paste does not have to get very smooth.
To the paste, add chopped spring onions, salt and mix.
Make small balls, roll them in rava to completely cover it.
Heat tava, spread some oil and fry the vadas on a medium low heat.