Soak dal in water for 4 hours. Blend in blender at medium speed using the minimum amount of water required to keep paste moving freely. Add salt and start heating oil.

Drop spoonfuls of batter in the hot oil using a large tablespoon. Fry until golden brown. Drop in water. Let it soak till ready to serve. Beat yogurt with milk. Add spice according to taste. Squeeze out water from the vada and add yogurt. Serve.