First, knead the wheat flour with a bit of salt and keep it aside.
Next, add ajwain, salt to the mandua flour and knead well. Rest this aside for 10 mins.
When you are ready to make the rotis, divide both the doughs into balls.
Take a wheat dough, press on the sides with center being thick, place the mandua dough in the center, cover from all sides and seal it well.
Dust with flour and gently roll out like a chapati.
Heat a tawa and cook the roti on both sides and grease with cooking oil.
Serve hot.