If you head to the bar of 1 Lombard Street, you are sure to come across a private detective or two among the financiers unwinding after the end of a busy day in the City. US firm Ankura Consulting's London investigators are regulars at the restaurant, which is a convenient five-minute stroll down Threadneedle Street. It is the perfect spot for investigators looking to quietly discuss a case over breakfast or run networking sessions with potential clients in this brasserie.

Half-open