Chilled Zucchini and Green Bean Soup with a Pesto Swirl

2 tablespoons extra-virgin olive oil1 small sweet onion, chopped1 pound zucchini, ends trimmed and thinly sliced4 cups reduced-sodium chicken broth1 package (10 ounces) frozen shelled edamame#189; pound green beans, ends trimmed#189; teaspoon salt, or to taste#188; teaspoon ground white pepper, or to taste#188; cup store-bought basil pesto#189; cup reduced-fat sour cream (optional)In a large saucepan over medium-high, heat the oil. Add the onion and zucchini and saute until very soft, about 10 minutes.Add the chicken broth and bring to a boil. Stir in edamame and green beans and simmer, uncovered, until the vegetables are soft, about 20 minutes. Remove from the heat and cool for 15 minutes.Transfer the soup, in batches if necessary, to a blender or food processor. Puree, then season with salt and pepper.Serve soup chilled or at room temperature. When serving, divide the soup among 6 bowls and swirl a spoonful of pesto into each. Top with sour cream, if desired.Serves six.@Recipe nutrition:Nutrition values per serving: 237 calories, 15 g fat (3 g saturated), 15 g carbohydrates, 5 g fiber, 14 g protein, 14 mg cholesterol, 350 mg sodium.