Take yoghurt in a bowl.

Add salt and mix well.

Season it with 1 tsp of oil, red chillies, asafoetida and curry leaves.

Crush the mustard seeds into coarse powder and mix it too with the yoghurt.

Wash the dal and soak it for 2 1/2 hours.

Then grind it like a thick paste by using little water.

Heat oil in a wok.

Take enough dough for about 5 to 6 vadas in a bowl and add enough salt.

Take the dough and make them into big lemon sized balls and place them on a plastic paper.

By using little water, flatten them and put a hole on them with finger.

Then slowly place them into the oil and fry them till golden brown.

:- You can make upto 5 to 6 vadas at a time.

Finally, slip in these vadas into yoghurt and allow them to soak for 2 hours.