To make the filling, heat the oil in a large non-stick pan. Add the cumin seeds, ginger, garlic, chillies and onions. Cook on a medium heat for 5 minutes or until very soft. Add the ground coriander seeds, ground cumin seeds and garam masala. Saute for a few minutes and add the rest of the ingredients. Combine and cook for a further 5 minutes stirring all the time. Remove from the heat and set aside.
To make the dough, take a large bowl and add the chapatti flour. Make a well in the centre and add the oil. Stirring with a spoon, slowly mix in enough hot water for you to be able to to form a dough. When cool enough to handle, bind until you get a soft and smooth, non-sticky dough. If it's sticky, add a little bit more oil and a dusting of flour and continue to bind.
Take a ball of dough, slightly larger than a golf ball and another of the cooled potato filling. The potato ball should be larger than the dough. Roll the dough to about 3-4" in diameter and place the potato ball on top.
Using your thumbs and forefingers, pinch the dough closed around the filling, starting in the middle and working your way outwards. The filling wrapped in dough should be fully enclosed with no gaps or holes. Flatten the ball using the palm of your hand. Dust with flour on both sides and flip over. You will need to roll the smooth side.
Keep rolling the dough, turning gently as you do. Ensure it is even all over and dust with more flour if necessary. Try to aim for 1/2mm in thickness.
Heat some oil or ghee in a non-stick frying pan and carefully slide in the paratha.
Cook on a medium heat on both sides until golden brown all over, adding more ghee or oil to the pan for added indulgence.