Billi-Bi of Cream of Mussels with Sorrel

There is a somewhat questionable story as to the strange name of this very French rich seafood soup with the unusual flavor. It is said to have been invented for, and affectionately named after, the American scientist, explorer and gastronome William Beebe. Somewhere in France. But where? I have found it in country bistros (including the Auberge) in virtually every part of France that is within a reasonable distance of the sea. But nowhere more regularly than in Normandy, and especially in