Prepare the Dough: In a large bowl, combine whole wheat flour and salt. Gradually add water and knead to form a smooth, pliable dough. Add 1 tsp oil and knead for another minute. Cover and let rest for 15-20 minutes.

Prepare the Filling: In another bowl, combine mashed potatoes, grated ginger, chopped green chili (if using), red chili powder, garam masala, cumin powder, chopped coriander, and salt. Mix well to ensure no lumps.

Assemble the Paratha: Divide the dough into equal small balls. Take one ball and flatten it slightly. Roll it into a small disc (about 3-4 inches in diameter). Place a spoonful of the potato filling in the center. Bring the edges of the dough together to enclose the filling, sealing it tightly. Flatten gently.

Roll the Paratha: Lightly dust with flour and gently roll out the stuffed ball into a flat disc, about 6-7 inches in diameter. Be careful not to let the filling break through. Use gentle, even pressure.

Cook the Paratha: Heat a tawa (griddle) or a non-stick pan over medium-high heat. Place the rolled paratha on the hot tawa. Cook for about 30 seconds until small bubbles appear.

Flip and Cook: Flip the paratha. Drizzle 1/2 tsp ghee or oil on the top side. Cook for another minute, then flip again. Drizzle ghee or oil on the other side. Press gently with a spatula to help it cook evenly and puff up. Cook both sides until golden brown spots appear and it's cooked through.

Serve: Remove from tawa and serve hot. Repeat with the remaining dough and filling.