Just got back from seeing Oasis at wembley and stopped for a curry on the way back at the passage to india on the Finchley rd, I had a lamb Xacutti and my friend went for a chicken Madras. The Xacutti was described as a Goan dish with malt vinegar and a "special blend of herbs and spices".
The dish in itself was very nice but pretty hot,I assume they used the same base sauce for both dishes,the best i can do to describe it was a lamb bhuna with very finely diced onion and green pepper and large chunks of tomatoes,it had a really thick sauce though,almost like a dhansak,it contained a lot of dessicated coconut and something else which thickened it, don't think it was lentils though,possibly pureed chickpeas? I reckon they add this as some sort of paste towards the end of the dish,and a fair bit of chilli powder.hope this helps.

Thanks,
I had a quick look on google yesterday,most of the acharis involve tempering whole pickleing spices at the start of the dish,mustard + fennel seeds seemed to crop up alot, so I'll see if i can incorporate this into it some how,I might even try one from scratch at some point,I'll have a crack at the cheats/DIY version for now and try and track down some mixed pickle of even Mango pickle,reckon that could be tasty.

Fantastic opportunity, looking forward to hearing how you get on.

Mine was the Alameda Tandoori in Ampthill around 1985, remember going for a fantastic curry in Bedford around the same time too.

I use the large Dutch green chillis widely availiable in the supermarket,the majority of the heat is in the membrane and the seeds so I deseed them first too but generally these are pretty mild and a good all rounder.
Be carefull of the really thin small thai chillis they are super hot,and can ruin a dish or a base sauce, guess it all depends how hot you like it.