2 large European cucumbers (2 1/4 pounds), halved and seeded—1/2 cup finely diced, the rest coarsely chopped
1 1/2 cups plain Greek yogurt
3 tablespoons fresh lemon juice
1 small shallot, chopped
1 garlic clove
1/3 cup loosely packed dill
1/4 cup loosely packed flat-leaf parsley leaves
2 tablespoons loosely packed tarragon leaves
1/4 cup olive oil, plus more for drizzling
Fresh ground white pepper
1/2 red onion, finely chopped
In a blender, combine the chopped cucumber with the yogurt, lemon juice, shallot, garlic, dill, parsley, tarragon and the 1/4 cup of olive oil. Blend until smooth. Season with salt and white pepper, cover and refrigerate for at least 8 hours or overnight.
Season the soup again just before serving. Pour the soup into bowls. Garnish with the finely diced cucumber, red onion and a drizzle of olive oil and serve.