There was a Dopiaza recipe in the takeaway supplement of the mag, I'm at work at mo but I will copy it for you tomorrow evening..
I did however find another recipe that looks better ill see if I can find it again now.
BTW Dopiaza means 'two onions' as you add onions cooked two ways x
ETA: the recipe I liked is this
Chicken Dopiaza Recipe - Food.com - 126582 you can substitute the oil for frylight or use a HEB in EV olive oil (not authentic but needs must) if using FL go careful not to burn the spices. The onions can have a little water added to aid softening.
Just to add texture I also like to thinly slice onions spread on a baking tray spray with FL and roast until crispy and top your curry with it.
Hope that helps x