Take the maida, wheat flour, salt and oil in a bowl and gradually add enough water and knead into a soft dough. Keep aside for 30 mins.
In another bowl, take the onions, poha, chilli powder, coriander leaves, garam masala powder, chaat masala powder and salt and mix everything well. Set aside for 20 minutes. The poha will absorb the water from onions.
Meanwhile, prepare the maida paste by mixing flour and water together.
Make tiny balls from the dough, dust with flour and roll them into circles.
Cut circles into semi-circles. Fold the sides of semi-circles to make a cone. Glue sides of cone with maida paste. Repeat with rest of the dough.
Heat oil for deep-frying and gently drop the samosas. Fry until they turn golden brown.