Cold soup. Some people like it, some don't. It can be a pretty wonderful, refreshing experience for the palate. It's a matter of debate where Vichyssoise originates from, but the story that's told over and over credits Louis Diat, a chef at the Ritz-Carlton in New York City where he supposedly served the soup in the summer of 1917. I learned this recipe for Vichyssoise while attending the French Culinary Institute. It was good, but I'm jealous Colman Andrews snagged Gazpacho for this week's cold soup recipe — that's my favorite.
Bring the chicken stock to a boil. Peel zucchini and blanch the peels in the stock. Drain, refresh, and set aside. Warm the oil in a small pot, add the leeks and sweat until tender but not browned. Slice the zucchini and add to the pot with the garlic. Cook gently for a few minutes to develop the flavor. Pour in the stock and add the potato and the bouquet garni. Season lightly and simmer for 15-20 minutes, or until the potatoes are tender.
Remove and discard the bouquet, and purée the soup in a blender, working in batches. Pass it through a fine chinois into a bowl or container set over ice and let chill, stirring occasionally. When the soup is thoroughly chilled, add the cream and adjust the seasoning and acidity if necessary. Serve the soup in chilled, shallow soup bowls garnished with the herbs and the lightly sauteed zucchini/squash mixture.