OK, so my friend has emailed me back and I have the goods on the lamb we ate a few years back. It is not a curry, however anyone with knowledge and skill could very easily adapt this method to incorporate whatever spices they deem desirable. It is not dissimilar to BIR method as it is done with a base sauce / gravy, but it has a more Mediterranean influence being a mixture of Italian sauce and Greek influence.
The original recipe comes from a book released by a Restaurant / Music venue located fairly close to my home. It is a small place with limited seating that provides musical entertainment by the countries top artists as well as internationals and up and comers along with really good food. It is run by a guy who in his own right was a successful musician here in the land of Oz. The recipe is based on Lamb Shanks but my friends did it with large chunks of boned out shoulder which they cooked for only 4 hours. A leg or full shoulder would benefit from the longer cooking but it is done when it's done.
First the sauce / gravy. Remember that this can be currified. It is the method we look at here.
Instead of Celery, Parsley and Basil, use Green Chilli, Indian Bay leaf and Fenugreek leaf, plus some Coriander Cumin and Cardamom pods and / or whatever else you think.