1. Cut one of the cucumbers into small dice, and set aside for garnish. Cut the others into large chunks. Combine cucumber chunks, garlic, yogurt, lemon juice, and water in a blender and puree until smooth.

2. Add scallions and mint leaves, reserving some of the mint for garnish, and puree briefly. Season with salt and pepper, and add more lemon juice if a tarter flavor is desired.

3. Chill until ready to serve. Stir well before serving, and ladle into bowls or mugs, garnishing each serving with a big spoonful of diced cucumber and a sprig of mint.