To make the dough, sift the flour and salt into medium bowl. Add 1 tablespoon of the clarified butter and rub the mixture between the palms of your hands to evenly distribute, letting the fat-coated flour fall back into the bowl. Continue until the flour is evenly coated. Add 6 tablespoons of the water, mix, and work until the dough comes together. Turn onto a lightly floured surface and knead for 4 minutes into a firm dough. Cover with a kitchen towel and let rest for 30 minutes.
To make the filling, in a large saute pan or skillet, heat the remaining 1/4 cup of clarified butter over medium-high heat. Add the coriander seeds and cook, stirring, for 10 seconds. Add the onions and ginger, and cook, stirring, until starting to caramelize, about 5 minutes. Add the garlic, chile peppers, garam masala, salt, turmeric, and cayenne, and cook, stirring, until fragrant, 30 to 45 seconds. Add the potatoes and cook, stirring until the potatoes start to color and become dry, about 3 minutes. Add the peas and cook, stirring, for 1 minute. Remove from the heat and add the cilantro and lemon juice. Stir to combine, then adjust the seasoning, to taste. Let sit until cool enough to handle.
On a lightly floured surface, knead the dough for 1 minute. Divide into 2 equal portions and roll each into a 1/2-inch thick rope. Cut each into 8 equal parts and roll into smooth balls. Place each ball on the floured surface and roll into a thin circle, about 6-inches in diameter. Cut each circle in half (2 semi-circles). Spoon about 2 teaspoons of filling in the center of each semi-circle. Brush the edges with water and fold the dough over the filling. Press the edges together to seal. Place on a baking sheet and repeat with the remaining ingredients.
Preheat the oil in a large pot to 350 degrees F. Add the pastries in batches and cook at 300 degrees F, turning, until golden brown, about 10 minutes. Remove with a slotted spoon and drain on paper towels. Serve hot.