Take yoghurt or dahi in a bowl.
Thin yogurt with water & add besan
Add red chilli powder, turmeric powder & asafoetida or hing.
Mix well into a slurry
Ensure everything is evenly dissolved
Heat ghee in a thick bottomed pan
Add whole red chilies and saute
Add mustard seeds, fenugreek seeds, cumin seeds & one sprig of curry leaves and fry till aromatic
Add the besan yogurt slurry to the pan
Add sliced green chilies
Keep stirring the slurry to avoid lumps. This is where it will start to thicken
Reduce heat when it comes to a boil