Dough: Place the wholemeal flour in a large bowl. Gradually stir in the oil and the water to make a soft, pliable dough.
Knead on a work surface for 3-4 minutes, then return to the bowl, cover and set aside for 1 hour.
Filling: Heat the oil in a frying pan. Add the mustard seeds and, when they start to pop, add the chilli, ginger, onions and curry leaves. Cook over a medium-low heat for 5 minutes, stirring occasionally, until the onions are soft. Add the turmeric and a little salt and sauté for 1 minute. Add the prawns and cook for 7-10 minutes, stirring occasionally, until they have turned pink and are cooked. Remove from the heat and set aside.
Divide the dough into 8 equal portions. Place one piece in the palm of your hands and roll it into a smooth ball. Lightly dust with flour, then place it on a board and roll out as thinly as possible, to make a paper-thin round, about 22cm in diameter.
Heat a flat cast-iron griddle or large, heavy-based frying pan. Brush with oil and, when hot, add a round of dough. Stir the eggs into the prawn mixture. Spread about 3 Tbsp of this filling on top of the dough on the griddle pan. Cook over a medium heat for 5 minutes or until browned underneath.
Lower the heat, then carefully turn the paratha over with a spatula and cook for a further 5 minutes or until the prawn mixture is well stuck to the paratha. Turn it over again and transfer the paratha to a board. Roll the paratha into a cylinder shape to enclose the prawn mixture.
Repeat with the remaining dough and filling. Cut each stuffed paratha in half to serve.