I will be spending the day after my birthday in London, and will be going to lunch with friends to celebrate. Later that evening, we'll be attending one of the Paralympic events in Olympic Park, so we are planning on grabbing a quick dinner from a street vendor then. For lunch, though, we'd like to go somewhere where we can sit and enjoy a nice meal. Any type of cuisine and atmosphere is open to possibility. As for price, I plan on spending a little (I realize London is pricey), but I'd rather not break the bank completely. Also, we will not be dressed for anything extremely fancy. Any suggestions?