Soak urad dal for overnight and grind it ina food processor or a grinder to a coarse paste.avoid adding water,if its hard to grind then add very little water.
Chopp the onion,green chilly,curry leaves,coriander leaves,ginger and keep it ready
Dry roast the urad dal and white rice for one minute and grind it to get a fine paste
Pour the batter into a large bowl and add onion,green chilly,pepper corn,curry leaves,coriander leaves,ginger,dry roasted paste and salt as required.combine well,cover it and allow it to ferment for atleast one hour.
Preheat oil in a vessel and wet hand in water,make a ball by using our dough,then dip your thumb in water and make a hole in the centre.shape all the vadas and fry it.
Serve the hot uzhunnu vada with coconut chutney