Soak 1 cup urud dal in sufficient amt of water for 1 hour and grind into a thick fine flour.
Add 1 tsp salt, 2-3 chopped green chillies, 1 tsp whole black peppers, a bunch of curry leaves and mix well.
On a plastic piece of paper place a ball of this and flatten it by hand.
Deep fry this in oil and turn over until the vada turns golden brown
Serve vadai with coconut chutney and/or Sambhar