Cucumber Soup

Blake and I were just treated to this wonderful cucumber soup, made by a friend of ours, and we wanted to pass along the recipe. It's a nice cool summer soup, from Deborah Madison's book Vegetable Soups.

THE SOUP
2 pounds cucumbers
1 cup buttermilk, whole milk yogurt, sour cream, or a mixture
1/2 cup coarsely chopped herbs, including basil, dill, cilantro, and/or lovage
Sea salt and ground pepper to taste
Zest and juice of 2 lemons
THE RELISH
2 tbs minced scallions
1 tbs minced dill
2 tbs finely chopped basil
2 tbs finely chopped dill
2 tsp olive oil

1. Peel and seed the cucumbers. Use one to make a cup of small dice and set it aside., then coarsely chop the rest. Puree in a blender or food processor with the buttermilk, chopped herbs, salt, and the zest and juice from 1 lemon. Chill.
2. Just before serving, toss the reserved diced cucumber with the herbs, a few pinches of salt, olive oil, and the remaining lemon juice and zest.
3. Taste the soup for salt, pepper, and acidity, adding more if needed, then serve in chillled bowls with the cucumber-herb relish.