Cold Yogurt-Cucumber Soup

2 medium cucumbers
1 1/2 cups plain yogurt
1/2 teaspoon salt
1/4 teaspoon dried mint flakes
1/8 teaspoon white pepper

Cut 7 thin slices from 1 cucumber; reserve. Cut all remaining cucumber into 3/4-inch chunks. Place half the cucumber chunks and 1/4 cup of the yogurt in blender container. Cover and blend on high speed until smooth. Add remaining cucumber chunks, salt, mint and white pepper. Cover and blend until smooth. Add remaining yogurt; cover and blend on low speed until smooth. Cover and refrigerate at least 1 hour.

Garnish with reserved cucumber slices.