Louis Diat was a brilliant French chef who worked at the Ritz Hotels in Paris and London. When Cesar Ritz opened the new Ritz-Carlton in New York he sent Diat to be the Chef de Cuisines at the new hotel. While there, Diat created 'crème vichyssoise glacée' a potato leek soup.
“But in summer, when the soup seemed to be too hot, we asked for milk with which to cool it. Many years later, it was this memory which gave me the inspiration to make the soup which I have named Creme Vichyssoise.”
Diat wrote several cookbooks, including 'French Country Cooking for Americans' and 'Cooking a la Ritz'.