Many restaurant chains sell chocolate on their pizza base as a dessert; chocolate is also known to complement many savoury dishes as a 'secret ingredient'.
There's a restaurant in London that incorporates cacao in some form or other in every dish. It's a bit of a gimmick in that in a lot of them it's not really noticeable, or just used very sparingly. It's probably easier to do with the constraint of "some form of cacao" than chocolate, though.
Many restaurant chains sell chocolate on their pizza base as a dessert; chocolate is also known to complement many savoury dishes as a 'secret ingredient'.