METHOD 

1. Wash And Soak Rice Washed Urad Dal In The Water For 5-6 Hours.
   
   
2. Finely Grind Make It Batter Add Salt And Leave It For Ferment 3-4 Hours.
    
3. Heat Oil In Pan Add Coriander Whole Cook For While Add Mustard Seeds And Red Chili Whole  When They Splutter  Now Add The Onions And Curry Leaves And Green Peas
   
   
4. Fry The Onions Till They Become Soft. Add The Red Chilies Whole And Ginger.Add The Turmeric Powder And Asafoetida. Mix Well.
    
5. Now Add The Boiled Mashed Potatoes And SaltCook For 2-3 Minutes Stirring Well. Add Chopped Coriander Leaves. Stir And Keep It Aside Potato Staffing.
    
6. Heat A Flat Pan Or A Flat Non-Stick Pan.
   
   
7. Spread The Dosa Batter With Ladle Or Smooth Round Bowl From Bottom In A Circular Motion On The Pan. Add Some Oil On Top Cook For While And  Take Out The Extra Batter From Top Of Dosa  And Make It Thin And Crisp .  
   
8. Spread The Potato Staffing  On One Side Of The Dosa.
   
   
9. Cover With The Other Half And Let The Dosa Cook For 15-30 Seconds.
   
   
10. Serve Masala Dosa Hot With Coconut Chutney And Sambar