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.