Creamy Cucumber Soup

• 1 tablespoon extra-virgin olive oil
• 2 cloves garlic, minced
• 1 small onion, diced
• 1 tablespoon lemon juice
• 4 cups peeled, seeded and thinly sliced cucumbers, divided
• 1 1/2 cups vegetable broth, or reduced-sodium chicken broth
• 1/2 teaspoon salt
• 1/4 teaspoon freshly ground pepper
• Pinch of cayenne pepper
• 1 avocado, diced
• 1/4 cup chopped fresh parsley, plus more for garnish
• 1/2 cup low-fat plain yogurt

Heat oil in a large saucepan over medium-high heat. Add garlic and onion; cook, stirring occasionally, until tender, 1 to 4 minutes. Add lemon juice and cook for 1 minute. Add almost all of the cucumber slices, broth, salt, pepper and cayenne; bring to a simmer. Reduce heat and cook at a gentle simmer until the cucumbers are soft, 6 to 8 minutes.Transfer the soup to a blender. Add avocado and parsley; blend on low speed until smooth. (Use caution when pureeing hot liquids.) Pour into a serving bowl and stir in yogurt. Chop the remaining 1/4 cup cucumber slices. Serve the soup warm or refrigerate and serve it chilled. Just before serving, garnish with the chopped cucumber and more chopped parsley, if desired.