Just thought I'd mention that anyone going to Goa should look into Parampara Curry Mixes. These have to be the most authentic Curry Mixes I have come across. Asda sell Shan Curry mix, but they are no-where near good enough.
You can buy them in alot of Asian Cash & Carry and now order online from www.puritytrading.co.uk where they do other food items which I have tried yet (Must order some).
We bought loads of Parampara mix back from Newtons in Candolim last year, but they only lasted a few weeks. Newtons were selling them for RS40 and in the UK they are £1.69 each.
Give them a try before you go and if you like them, you can bring loads back!