Put all the ingredients into a blender or food processor, season with salt, and process to make a paste. Transfer to a large bowl, cover, and allow to chill in the refrigerator for about 1 hour.
Shape the mixture into plump patties, place in idli moulds, and steam in a steamer or pressure cooker for about 10 minutes, or until cooked. If using a pressure cooker, don't apply the weight or whistle. If you don’t have idli moulds, steam the patties in a steamer.
Remove the patties and lightly pat on kitchen paper (paper towels) to remove any extra moisture.
Heat a little oil in a non-stick pan over medium heat, add the patties and cook, pressing with a wooden spatula, for about 10 minutes, or until lightly browned on both sides.