The photo shows me wearing a pair of Moroccan qandrissi trousers, a type of men's harem trouser. In French, they are called sarouel, from the Arabic sirwal or سِرْوَال. I mentioned the style for its comfort and elegance in my Dr Dobbs essay Dress Code. This pair, like the top, came from Omar Serroukh's shop "Fez" at 71 Golborne Road in London. See also these photos and these.
22nd March 2013