1Drain the soaked dal and grind coarsely without water. Heat 1 tbsp oil, add asafoetida, fennel and coriander, then the dal and besan. Stir on low 6 to 8 minutes with chilli, garam masala, amchur and salt. Cool and divide into 4.
2Rub the maida, salt and ghee until the mix holds when pressed. Knead a soft dough with about 80 ml water. Rest 15 minutes.
3Divide the dough into 4. Cup each piece, fill, seal and press gently into a flat 9 cm disc.
4Heat the oil until warm, not hot. Slide in the kachoris gently and fry on low heat for 15 to 18 minutes, turning, until crisp. Take care with the hot oil.
5Simmer the tamarind, jaggery, cumin and 150 ml water for 8 minutes and strain. Blend the coriander, mint and green chillies with a splash of water and salt. Whisk the curd with sugar.
6Toast the buns cut side down. Spread green chutney, add a kachori and crack its top lightly. Spoon on curd and tamarind chutney, then onion, sev and chaat masala. Close and serve.
Serve it like this
Serve on a steel plate wrapped in a paper napkin, extra sev on the side and a small spoon for the chutneys that escape.