Adapted from Gourmet magazine
1 small boiling potato (1/4 lb), peeled and cut into 1/2-inch cubes
1 small onion, finely chopped
2 cups low-sodium chicken broth
1 cup heavy cream or half & half
4 cups watercress, coarsely chopped (one large bunch)
Simmer the potato, onion, broth, and cream uncovered in a 3 to 4-quart heavy saucepan until the vegetables are soft (about 10 minutes). Stir in the watercress, and cook the mixture uncovered for an additional 3 minutes over moderately low heat.
Purée the mixture in two batches in a blender until very smooth (be careful when blending hot liquids). Force the soup through a fine mesh strainer into a bowl, pressing hard on the solids and discarding them. Season with salt and pepper. Let soup stand uncovered for 45 minutes until cooked. Chill in the refrigerator for 1½ hours. Soup can be chilled and kept covered for up to two days.
Makes 4 servings
Allergy Warning: Contains milk