Most people assume that vichyssoise—the chilled summertime soup made of leeks, potatoes, and cream—is French. As it happens, this staple of international fine dining was invented in New York City to celebrate the 1917 opening of the roof garden of the city's original Ritz-Carlton Hotel. There is a French connection, though: the soup's creator was French-born chef Louis Diat, whose inspiration was his mother's much heartier potato and leek soup. As a child he found it too hot to eat and poured cold milk into it to make it more palatable; the lesson was not lost. Refining the concept in 1917, Diat named the soup after the city of Vichy, near where he grew up. (The moniker he devised perpetually confuses the French, incidentally, because in France "Vichy" generally connotes a dish made with carrots.)
Vichyssoise is the Cinderella of soups: it's humble home cooking transformed into polished restaurant fare. And making it couldn't be simpler. Leeks and onions are sautéed in butter; potatoes then get added to the pot, along with water, and simmered until tender; the ingredients are then pressed twice through mesh sieves and enriched with milk and cream. A sprinkling of finely chopped chives invariably tops a true vichyssoise. When made properly—and with the best ingredients—the soup is incomparably smooth and sumptuous.
Vichyssoise has fought hard to keep its supposed Frenchness. When the high-living steel honcho Charles M. Schwab first tasted it, it was listed on the Ritz's menu as "crème vichyssoise glacée"; Schwab liked it so much that he reportedly ordered seconds. During the Depression, though, in a moment of professed patriotism that predated the notion of freedom fries, the Hotel Association of New York City suggested to the Ritz that business might pick up at the hotel's restaurants if they stopped using French terms on their menus. Thus began the gradual modification of the soup's original name: "crème" became "cream", and over time we have come to know it as just plain vichyssoise. Today, though, the soup is as cool and subtle as it was eight decades ago—a fitting homage to Diat, of whom the author and illustrator Ludwig Bemelmans once wrote, "He never raised his voice, he never lost his temper."