Diana Sturgis' Curried Cauliflower & Leek Soup

Freeze the chicken broth until the fat congeals on the surface, about 20 minutes. Discard the fat.

In a large saucepan, cook the leeks in the oil over moderately low heat, sirring occasionally, until partially wilted, about 7 minutes. Add the potato and curry powder and cook and stir for 3 minutes.

Add the cauliflower, defatted broth, water and bay leaves. Bring to a boil over high heat. reduce heat, cover and simmer until the vegetables are very soft, about 30 minutes.

Discard the bay leaves. reserve 1 cup of the cooking liquid; pour into a small saucepan. Boil until reduced to about 3 tablespoons.

Working in batches, puree the vegetables and the remaining cooking liquid in a blender. Add the reduced cooking liquid to the soup in the blender. Season with sea salt and pepper.

To serve: ladle into soup bowls and, if desired, top each serving with 1 tablespoon of the yogurt which you swirl lightly into the top of the soup.