- 1 teaspoon olive oil
 - 1 large onion, chopped
 - 1 1/2 teaspoons ground cumin
 - 1 1/2 pounds zucchini, trimmed, cut into 3/4-inch pieces
 - 2 14 1/2-ounce cans low-salt chicken broth
 - 2/3 cup chopped fresh basil
 - 4 tablespoons plain nonfat yogurt
 - Sliced fresh basil
 
- Heat oil in heavy medium saucepan over medium heat. Add onion; sauté until tender, about 5 minutes. Add cumin; stir until aromatic, about 30 seconds. Mix in zucchini. Add broth; bring soup to boil. Reduce heat; simmer until zucchini is very tender, about 30 minutes. Cool slightly.
 - Mix 1/3 cup chopped basil into soup. Working in batches, puree soup in blender until smooth. Transfer to bowl. Season with salt and pepper. Cover; chill until cold, about 3 hours. (Can be made 1 day ahead. Keep refrigerated.)
 - Ladle soup into bowls. Top each with 1 tablespoon yogurt and sliced basil.