In a deep bowl add the flour, rava, nigella seeds, baking soda, salt & oil.

Knead the mixture for 5 minutes without adding water.

Now start adding water (keep adding in little amounts) in the dry mixture & keep kneading until a firm dough is formed.

Now make medium-sized dough balls (like we make for paranthas) & roll big-sized thin rotis.

Cut out small papdi shaped puris from the big-sized rotis. Make some holes in the puris with the help of a fork.

Heat oil in a kadhai & fry the puris in it until they turn brown.