The dal is plain Mung dal (Mung dal yellow). First you need to soak the dal for atleast half an hour. Then in an open pan boil the dal with salt, water and turmeric till buttery smooth. The flavors come from slow cooking the dal. We, at home just add freshly pounded black pepper along with some ghee/ butter but you can give a tadka of red chilli powder.
The green chutney is regular mint coriander chutney with extra tamarind juice. Also, I guess they have a separate tamarind chutney too (not sure about the Doli but ma y other vendors do use that)….tamarind juice with hint of ajwain, kaala namak, bhuna jeera powder, pinch of hing, sugar etc.

I think it’s made with moong dal but not very sure about it. also their green chutney is out of this world. if you know the recipes, please let me know.