1. Crush the sweet corn. Mix onions, salt, red chilli powder and turmeric powder in a bowl, crushing with your fingers. Add the sweet corn and mix.
2. Add gram flour, wheat flour and corn meal and knead with enough water to a dough. Cover the dough with damp cloth and rest for 15 minutes.Heat a non stick tawa.
3. Divide the dough into equal portions and roll into balls. Dust each ball with a little dry flour and roll carefully into thick rotis.
4. Place the roti on the hot tawa and roast on medium heat for ½ minute.
5. Turn over, drizzle a little oil all around and turn again. Cook, turning a few times, till both sides are well done. Serve hot.