Mix wheat flour, rice flour, cooking soda, salt, green chili, ginger, black peppercorn well
Add sour curd and mix well
Add water little by little and mix the batter such that no lumps are formed
Make into a rava dosa consistency
Heat a dosa tawa, bring it to medium flame (I used appam tawa though)
Take a ladle full of batter and pour over the tawa from outside to inside to form a semi-circle
Take another ladle full of batter and pour over the tawa from outside to inside such that it will fill the rest of semi-circle
Add oil over the edges
Once the edges turn golden brown reverse the dosa and allow it to cook for a minute
Serve hot with any or all of chutneys