In a large bowl, combine the all-purpose flour and salt. Pour in the 1/4 cup of warm oil and rub it thoroughly into the flour using your fingertips until the mixture resembles coarse breadcrumbs.

Gradually add water a little at a time and knead to form a firm, stiff dough. Cover with a damp cloth and let it rest for 30 minutes.

Drain the soaked moong dal completely. Transfer it to a food processor or pulse grinder and pulse a few times to get a coarse, grainy texture without making a smooth paste.

Heat 1 tablespoon of oil in a pan over medium heat. Add the crushed fennel seeds, cumin seeds, and asafoetida. Add the besan and stir for 1 minute until fragrant. Add the ground moong dal, red chili powder, garam masala, dry mango powder, and salt. Stir continuously for 4 to 5 minutes until the filling is dry and crumbly. Remove from heat and let cool.

Divide the rested dough and cooled filling into 8 equal portions. Roll a dough ball into a small circle, place a filling portion in the center, bring the edges up to enclose the filling, and pinch to seal securely. Flatten gently with your palm.

Heat oil in a deep pan over low heat. Slip a few stuffed kachoris into the warm oil. Fry slowly on low heat, turning occasionally, for 12 to 15 minutes until the pastry is golden brown and crisp. Remove with a slotted spoon and drain on paper towels.