Sieve bajra flour, atta and salt together. Add onion, carrot, green chillies and carom seeds. Add water, a little at a time and knead into medium soft dough. Do not knead the dough excessively. Divide the dough into eight equal portions and roll them into balls (pedas).
Wet your palms with water, take a portion of dough and pat it between your palms to make thin rotis of about four to five inch diameter.
Make them as thin as possible. It takes some practice before you can make thin bajra rotis. Heat a non-stick tawa and place a roti on it.
First cook one side for about half a minute on medium heat and then flip it over and cook the other side similarly.
Reduce heat and cook on slow heat on both sides till the bajra roti is slightly browned. Repeat the same method with the remaining dough.