Hi all ,
I, like SD, have tried adding the TSP of mixed spice ( CA's ) and 0.25 TSP of All Purpose Seasoning as well as 1 Tsp of Tomato Puree mixed with a little water .. I know the concept of the dish was to be dry and at the temperature my pan was at , the liquid was gone in seconds. I think it tastes better but I'm going to try the cassia bark too next time for even more flavour ... this is a regular side dish for us now so thanks to all that have contributed !! 
Fantastic - and further proof that recipes are there to be experimented with and adapted.
Just a thought on the cassia bark...
I've never come across any in the saag bhajis I've had in BIRs (and I have had a lot over the last 30-odd years!).
That's not to say that some don't add a bit, but cassia bark is tough old stuff (I suppose it would be, what with it being bark), and takes a little time to release its flavours. If using it I'd suggest adding it to the hot oil first and giving it a good stir fry before adding the garlic and onions, etc.
As an afterthought, the only occasions that I've come across cassia bark in BIR dishes (apart from when I've been lucky enough to blag some of the staff curry), it's always been 'old'. By this I mean extremely well cooked, to the point where it's almost soft.
This would suggest that it's come from the stockpot, rather than added fresh to a dish.