Wash and soak urad dal overnight.

In the morning, drain water and grind along with red chillies and pepper till coarse. In the end, add the chopped onion and grind some more till the onion is well mixed,

Leave the batter in the fridge for 5-6 hours to slightly ferment and rest.

When ready to fry, take a little batter in hand and using a grease ziploc or plastic bag spread the batter and make a hole using your fingers.

Deep fry in medium hot oil till golden brown. Set aside for cooling. Repeat for all the batter

To assemble the dahi vada (curd and other quantity for 6-8 vadas), whisk together curd and a little water to make smooth and a little thin curd.

Add salt and lots of coriander leaves to the same.

In a small tadka pan, heat oil and add mustard seeds, curry leaves and dry red chillies to the same. Pour over curd and mix.

In a small bowl, take hot water and dip the vadas in that for 30 seconds. Squeeze out the water. This also takes away excess oil from the vada and makes it lighter to eat.

Slide the vadas in the prepared curd and repeat for all the vadas.

Chill this for 2-3 hours and serve happiness in a bowl.