This Friday Trafalgar Square will host a traditional Malaysia night market (Pasar Malam). The event starts from 3pm to 10pm and Malaysia Kitchen has promised that there would be about 20 Malaysian restaurants with stalls serving up delicious food for Londoners to sample.
If you are planning to attend I suggest to sample the beef rendang, satay (hopefully they have them properly grilled unlike the tacky oven based stuff they serve in London-based Thai restaurants) and laksa. There will also be stalls selling authentic ingredients like spices and pastes.
I will be there with some mates, hopefully throughout the evening. If you want to meet up @ on twitter.