Here is an article I came across in The Guardian today
detailing another article in The NY Times by 'Freakonomics' author Stephen J Dubner. Needless to say, on his trip to London, the author fell into some tourist traps and had some "English stereotype of potted meat, soggy pastry, and vegetable mush".
London has of course come a long way when it comes to food and restaurants but it's still possible to have bad food if you don't do your research. So, advice to travellers, do your research, consult restaurant guides such as Time Out, Toptable and London-eating, which also have special offers and of course ask for tips from the locals!