It is not uncommon to see recipes that include a beurre blanc sauce to which heavy cream has been added as a "stabilizing agent". This is a point of contention amongst many culinary enthusiasts and can be heavily frowned upon. Chef Anthony Bourdain famously wrote in his novel Bone in the Throat: "There is no, I repeat, no, cream in a real beurre blanc ... You see any mention of cream in there? No ... you put cream in there, it ain't a beurre blanc.
The cook Clémence Lefeuvre (née Clémence Prau) invented beurre blanc, apparently by accident, some time around the beginning of the 20th century. She served this sauce at her restaurant "La Buvette de la Marine" in the hamlet of "La Chebuette" in the village of Saint-Julien-de-Concelles situated on the banks of the Loire River a few kilometers upstream from Nantes. Legend holds that she intended to prepare a bearnaise sauce to go with pike fish but forgot to add the tarragon and egg yolks. Some sources claim that this invention occurred while she worked as a cook for the Marquis de Goulaine at Chateau de Goulaine. Aristide Briand, long-time Prime Minister of France and Nobel Peace Prize laureate, said at her death in 1932 that her passing "was a bit like national mourning".