Soak urad dhall & rice for couple of hours and grind it really nice adding the chillies and required amount of salt. The batter consistency should be like bajji consistency. Now make balls out of paruppu usli. Preheat oil in a pan. Dip the usli urundai in urad dhall batter and deep fry it till it becomes golden brown. This tasted so fantastic and kids also liked it very much.