Surfing the Internet will undoubtedly turn up plenty of useful niblets of information with little effort. But it is also an efficient way of reminding yourself how myths get established as facts if they are repeated often enough. Billi Bi is a case in point.
All the sources (none of them eyewitnesses or even secondhand) agree that this yolk-and-cream-thickened mussel soup was invented in France. The most widely attested version of the legend names Louis Barthe