Add some salt & cumin seed in paste and mix nicely.
Now take a pan heat the oil & start to make vada.
Now take a VESSEL put 1 Cup curd & 4 cup water and mix it.Then put all Vada in mixture and leave for 1/2 to 1 hour.
Take a bowl put 2 Vada with some water & curd mixture.Add some curd, red Chili powder, Black salt, roasted cumin powder & sweet tamarind chutney.If u want than also can add coriander chutney
Notes
Batter will be thick. If batter is ready then immediate make vada.