For the kanji::- Take soaked mustard seeds in a mixer jar.grind and make a smooth paste. transfer this paste into a deep bowl and add water,salt,hing,red chilli powder and jaggery and mix well with spoon.
For the vada::-- blend the soaked dal and make a fine paste without using any water. Heat oil in a kadhai. Wet your hands and take 1/2 tsp of dal paste on your palm and shape this into a circle.
Drop it in oil.make all vadas like this and deep fry on medium heat till it turns golden brown of all sides. . Drain it in an absorbent paper.
Add all vadas in the prepared kanji water.cover and rest for 2 days. After 2 days you can serve this kanji vada. This is best source of digestion.
