Marinate the paneer with the hung curd, pesto, chilli powder (if using), salt & pepper. Keep aside for at least 15-20 mins
In the meanwhile prepare the dough by mixing the whole wheat flour with the oil and salt in a shallow bowl (or a flat vessel used to knead dough). Add the water little by little and bring the mixture together into a ball. Knead with the heel of your palm using a stretching motion to form a smooth dough with no cracks on the surface. Cover and keep aside till required.
While the dough is resting, prepare the filling. Heat oil in a non stick kadhai and add the onions and fry until they turn pale (translucent)
Next, add the marinated paneer and lightly fry them for half a minute. Remove from heat.Assemble
Pinch out lemon sized balls from the dough and roll them out into chapathis.
Heat a skillet/tawa and fry the chapathis lightly - do not brown them too much as they will turn hard. Remove and place covered in a clean towel in a hot box (casserole).
Heat another frying pan on a medium low heat and drizzle a few drops of oil and add the beaten egg. Let it gently cook on a low heat so that it doesn't brown quickly.
As one side is gently frying, place the prepared chapathi over the egg mixture and continue to cook until the base loosens up easily and helps you to flip the chapathi+egg. Fry the other side for a few seconds (to ensure that no raw mixture remains uncooked)
Remove onto a plate and place the paneer mixture in the centre in a vertical line. Add the sliced onions and chopped coriander, sprinkle lime juice and then roll the chapathi. Cover with foil or butter paper if desired and serve hot.