Rinse the urad, chana and moong dal and soak them for approximately 4 hours.
Then grind them together.
Add the oats powder in it.
Mix it well and add the baking soda in it and then also mix it.
Grease the apam pan with oil and pour the batter in it.
Cook both sides of the vadas.
Mix half of the salt in water.
Put all the vadas in the salt water.
Beat the curd.
Add the remaining half of the salt and crushed ginger and chilli in it and mix it well.
Then for tampering put oil in a ladle and then add the punch photon in it. When the mustard in the punch photon crackle then add the curry leaves and red chilli in it.
Add the beaten curd over the vadas and then tamper it .
Roast the cumin seeds and red chilli and make a powder.
Sprinkle the the roasted cumin and red chilli powder over the Dahi vadas.
Now your mixed dal oats dahi vadas are ready and serve it.