Soak yellow moong dal for 2-3 hours
Then grind the dal n make bhajiya batter consistency.
Then add black pepper , green chilly n salt n mix it.
Then add soda bi carb n 1tsp hot oil n deep fry vadas in hot oil.
Then mix fennel seeds crushed n yellow mustard splits n salt in 1/2ltr water n mix it .
Then add vadas into mustard water .keep this aside for 1 or 2 days n then eat as appetiser or as starter.