- 4 tablespoons unsalted butter
- 1 medium onion, finely chopped
- 1 clove garlic, minced
- 1/2 pound sorrel leaves, stems removed
- 2 stalks celery, finely chopped
- 3 cups vegetable stock or water
- 1 tablespoon chopped parsley plus extra for garnish
- 1 teaspoon coarse salt
- 1/2 teaspoon freshly ground black pepper
- 1/4 teaspoon ground nutmeg
- Sour cream or plain yogurt for garnish
Heat butter in a large saucepan over moderate heat. Add onion and saute until soft, about 10 minutes. Add garlic and saute another 2 minutes. Add sorrel and celery and cook for about 5 minutes, or until sorrel is wilted. Add stock or water, parsley, salt, pepper and nutmeg. Simmer for about 20 minutes.
Remove saucepan from heat and puree soup in batches in a blender or a food processor fitted with the metal blade. Adjust seasonings and transfer soup to a container. Cover and refrigerate until chilled through.
To serve, ladle chilled soup into bowls and garnish with chopped parsley and a dollop of sour cream or plain yogurt.