Thanks Paul .. I was panicking a little there !
I used neck fillets and cooked them for 3.5 hrs on 'low' ... they are moist and melt in the mouth. Accidentally they were cooked for 1.5 hrs then rested for 2 hours during a power cut and then back on for another 2 hrs. Maybe a method I'll adopt since they're better than I would have thought possible.
The base tastes very much of lamb but not curry at this stage

I'm going to reduce it back to it's original 450ml and by then should have a wonderfully lamby gravy to cook with .. I'll post thoughts on the bhuna tomorrow