Instructions

 for the potato stuffing

Place potatoes in large saucepan, add cold water to cover by 1 inch, and bring to boil over high heat. Reduce heat to maintain simmer and cook until potatoes are very tender, about 16 minutes. Drain well and process through ricer or mash with potato masher until completely smooth. Set aside and let partially cool, about 20 minutes.
 Stir cilantro, ginger, amchoor, cumin, salt, Thai chile, kalonji, and ajwain into potatoes. Season with salt to taste. Cover and set aside. (Potato stuffing can be refrigerated for up to 24 hours; let come to room temperature before using.)

 for the dough

Pulse flour, salt, and sugar in food processor until combined, about 5 pulses. Add oil and pulse until incorporated, about 5 pulses. With processor running, slowly add cold water and process until dough is combined and no dry flour remains, about 30 seconds. Transfer dough to clean counter and knead by hand to form smooth, round ball, about 30 seconds; transfer to bowl, cover with plastic wrap, and let rest for 30 minutes.
 Divide potato stuffing into 8 equal portions and roll into balls (they will be about 1½ inches wide); cover with plastic. Divide dough into 8 equal pieces, about 1¾ ounces each, and cover loosely with plastic. Working with 1 piece of dough at a time, form dough pieces into smooth, taut balls. (To round, set piece of dough on unfloured counter. Loosely cup your hand around dough and, without applying pressure to dough, move your hand in small circular motions. Tackiness of dough against counter and circular motion should work dough into smooth ball.) Let dough balls rest, covered, for 15 minutes. While dough balls rest, line rimmed baking sheet with parchment paper.
 Roll 1 dough ball into 4-inch disk on lightly floured counter. Place 1 stuffing ball in center of dough disk. Gather edges of dough around stuffing to enclose completely; pinch to seal. Place seam side down on lightly floured counter, gently flatten, and lightly and gently roll to even ⅛-inch-thick round (about 8 inches wide). Transfer to prepared sheet and cover loosely with plastic. Repeat with remaining dough balls, stacking parathas between layers of parchment.
 Heat 10-inch cast-iron skillet over medium heat for 5 minutes, then reduce heat to low. Brush any remaining flour from both sides of 1 paratha, then gently place in hot skillet, being careful not to stretch paratha. Cook until large bubbles begin to form on surface, underside of paratha is light blond, and paratha moves freely in skillet, 30 to 60 seconds. (Paratha may puff.) Using metal spatula, flip paratha; brush with ghee. Cook until underside is spotty brown and moves freely in skillet, 20 to 60 seconds, pressing any puffed edges firmly onto skillet with spatula to ensure even contact.
 Flip paratha back onto first side. Repeat brushing with ghee, pressing, cooking, and flipping once more until paratha is even more spotty brown on both sides and no longer looks raw, about 30 seconds per side. Transfer cooked paratha to second rimmed baking sheet, let cool slightly, then cover loosely with dish towel.
 Repeat with remaining parathas, wiping out skillet with paper towels between each paratha and briefly removing skillet from heat if it begins to smoke or if paratha browns too quickly. Serve hot. (Parathas can be stacked between layers of parchment paper, placed in zipper-lock bag, and refrigerated for up to 2 days; to refresh, heat 10-inch cast-iron skillet over medium heat for 5 minutes, then reduce heat to low. Cook paratha until warmed through, flipping 3 times, 10 to 15 seconds per side.)