We’re in love with leeks this January, so we’re partnering with our friends at Food52 to share tips, insights and recipes featuring the onion’s cousin.
Hot or cold? American or French? A classic vichyssoise (pronounced veeshee-swahze) is, at its core, a puree of potatoes, leeks, cream, onions, and stock. And while the viscous soup's ingredients are simple, its origins remain a bit cloudier. Julia Child called it an "American invention," while other culinary historians waver between whether it's genuinely French or American.
Cold vichyssoise, though, is American. In 1910, Louis Diat first chilled the soup for New York City's Ritz-Carlton Hotel. (Earlier cookbooks and published recipes served the soup hot.) Somewhere along the line, though, chilled vichyssoise became "classic."
Vichyssoise is like the less fancifully-named potato leek soup, but with a bit more oomph (and more cream). You start off by sautéing leeks and onions in a healthy amount of butter—cooking low and slow to ensure they soften, but don't take on any color. We want an off-white soup, not an off-white soup with brown flecks.
From there, potatoes and stock go into the saucepan and everything simmers until the vegetables are tender. The mixture goes into a food processor or blender and is pureed until smooth. Here's where vichyssoise technique varies a bit: The President's Own White House Cookbook instructs you to add milk, cream, nutmeg, salt, and pepper, bring to a boil, let cool for 10 minutes, and then blend the vichyssoise a second time. In Masters of American Cookery, the puree is thinned with cream to reach desired consistency (read: whether you want thin or thick soup), and brought just shy of a simmer before serving.
From there, you can chill the soup, however we prefer vichyssoise hot, where the humble marriage of potato and leek becomes something that's smooth and soothing (some might even say soupier).
Whatever the temperature, serve vichyssoise with a dollop of sour cream and a smattering of chopped chives. It might be French. It might be American. But it's always mighty fine.