Also, Did you manage to figure out what went wrong with batch #10?. I think for best results the gravy needs to rest overnight.
I am a firm believer in aged curry dishes, not only but especially traditionally cooked red meat, being better than straight from the pot. I've never experienced any such benefit from aged base gravy. I often cook finished dishes using freshly prepared gravy and then follow up with using the rest over the following week. I have not noticed any improvement in this, or any other gravy from fresh to aged.
The quality of the cassia is key
Mick, if this is trying to imply that any supposedly "failed" attempt in producing the completed balti gravy, and subsequent balti dish, is singely down to the poor quality or age of the cassia, I for one am not buying it. The first thing I investigated when I was unimpressed by the dish was the possibility of "old" spices, not limited to but including cassia. I immediately went out and bought new fresh packets of cardamom, star anise, tej patta and cassia bark both locally and shortly afterwards from the busiest, highest turnover Indian grocer in the centre of "Little India" Australia, ie: Udaya in Wentworthville . It made zero discernible difference.
At the risk of sounding like a broken record, the gravy is great when used as you would any other, but the basic Balti Chicken just didn't do it for me.
What I have found does make a significant difference to this gravy, as it would to any, is the amount of fresh coriander used. I don't mind a bit but if you use too much it is the dominant flavour by far.