Pre-heat oven to 180 degree.Line a cookie tray with parchment paper.
In a medium bowl mix all the dry ingredients flour,cornmeal,baking powder,baking soda,salt,nigella seeds,cumins and chilli flakes.
In another medium bowl whisk butter till it looks fluffy and pale white in colour.
Add sugar and whisk till sugar is mixed properly and the mixture looks fluffy.
Add yoghurt ,whisk for another 4-5 minutes.
Add the dry ingredients and mix just until everything is incorporated.(don't over mix).
Roll into balls of equal size(The mixture might be slightly wet but can be handled by hand).
Place the rolled dough balls in the prepared sheet one inch apart(the cookies will expand slightly while baking). With a fork dipped in flour press the cookies at the center and flatten slightly.
Bake for 12-15 mins. Cookies might be little soft to touch at the centre,so don't get tempted to bake more time.