- 1 tablespoon vegetable oil
- 1 cup finely chopped yellow onions
- 1 1/2 teaspoons salt, or more to taste
- 1/4 teaspoon freshly ground white pepper, or more to taste
- 1 tablespoon minced garlic
- 6 large cucumbers, peeled, seeded, and chopped (about 6 cups)
- 1/2 cup finely chopped green onions (green and white parts)
- 1/2 teaspoon dried dill
- 4 cups Chicken Stock or 
- canned low-sodium chicken broth
- 1/4 cup minced fresh flat-leaf parsley
- 1 cup plain yogurt
- 1/2 pound smoked salmon, finely chopped
- Heat the oil in a large heavy saucepan over medium-high heat. Add the onions, salt, and white pepper. Cook, stirring occasionally, until the onions are softened, about 4 minutes. Add the garlic and stir until fragrant, about 1 minute. Add the cucumbers, green onions, and dill. Cook until the cucumbers are starting to soften, about 3 minutes. Add the stock and bring to a boil. Reduce the heat to medium-low and simmer, stirring occasionally, for 20 minutes.
- PurÈe the soup with an immersion blender or in batches in a food processor or blender. Transfer the soup to a bowl. Cover and refrigerate until cold, at least 2 hours.
- Stir the parsley and yogurt into the soup. Refrigerate for at least 2 more hours, or overnight, to chill thoroughly.
- To serve, season the chilled soup to taste with additional salt and white pepper if needed. Ladle the soup into bowls and garnish each serving with a spoonful of chopped smoked salmon.