Melt the butter in a large pot over medium heat. Add the shallots and cook until soft. Stir in the cucumbers, vinegar, stock, water, chillies, parsley, coriander, lemongrass, garlic, fish sauce, soy sauce and ginger. Season to taste with salt and pepper. Simmer over medium heat until the cucumbers are soft, about 20 minutes. Stir in the sour cream until evenly blended, and simmer 10 minutes more.
Had an excess of home grown cucumber and found this recipe. Very quick and easy as I had all the ingredients apart from the Coriander. I have a heavy cold and this soup is just what the doctor ordered!! Delicious. - 13 Nov 2010