I am experimenting with various curry recipes coming from chefs and roadside "dhaba" cooks on youtube, but i cant figure out what exactly is the ingredient/combination of ingredients that gives the curries the magical pungent sweet flavour.
To start with, i bought home a parcel of my favourite curry - "Kadai Paneer" and used it as a control for my experiment ;)
I tried using a few spice powders - fennel , cardamom and mace - that, for a brief period of time during the process of cooking, gave out fragrance that came very close to the control. I could not maintain the intensity of that fragrance in my dish though.
Cashew and cream also give some sweetness to the dish and i managed to get somewhoat closer to the control. I suspect the presence of some additional sweet flavoured spice/tastemaker that enhances the sweetness of the dish.
I know that these recipes are closely guarded and secrets are not given out easily. Still trying to give it a shot though - maybe some kind soul would like to help as to what really goes in these curries that gives them that exceptionally strong sweet and creamy fragrance.
EDIT 1: Thanks for all the awesome answers here. By my own experimentation and further comparison , i realised that 1) The curry i prepare has some bitterness. Probably because i grind the spices with the tomatos/onions ?? 2) Adding more fat(cream, butter) gets my dish closer to the control. 3) There is **not a hint** of bitterness in the restaurant-curry. How come ??!!