Watercress Soup with Pickled Cucumbers

• HEALTHY
• MAKE-AHEAD

Ingredients

1. 3 tablespoons extra-virgin olive oil
2. 1 large leek, white and tender green parts only, thinly sliced
3. 2 cups low-sodium chicken broth
4. 2 cups water
5. One 8-ounce Yukon Gold potato, peeled and sliced 1/3 inch thick
6. 1/2 pound watercress, coarsely chopped (5 cups)
7. 1 cup whole milk
8. 1 cup skim milk
9. Salt and freshly ground pepper
10. 1/2 European cucumber, peeled
11. 1 tablespoon unseasoned rice vinegar

1. In a large saucepan, heat the olive oil. Add the leek and cook over moderate heat, stirring, until softened, 3 minutes. Add the broth and water and bring to a boil. Add the potato, cover and simmer over low heat until tender, about 15 minutes. Add the watercress and cook until bright green, about 2 minutes.
2. Working in batches, puree the soup in a blender. Return the soup to the saucepan. Add the whole and skim milk and season with salt and pepper; keep warm.
3. Meanwhile, trim the peeled cucumber to form a rectangle. Cut the cucumber crosswise into very thin slices. In a medium bowl, combine the rice vinegar with a large pinch of salt. Add the cucumber slices and toss well. Let stand until they have softened, about 5 minutes.
4. Ladle the soup into bowls. Garnish with cucumber slices and serve.