1/2 cup walnut hearts, toasted and finely chopped
2 cups plain yogurt (not Greek yogurt)
1 1/2 cup ice water
1/2 to 3/4 of a seedless English cucumber, finely chopped (about 1 to 1 1/2 cups chopped), plus a few cucumber slices for serving
1 cup chopped fresh herbs (parsley, basil, dill, mint)
1/2 cup gold raisins
3/4 tsp sumac, more for later (optional)
In a large bowl, whisk together yogurt and iced water. Stir in finely chopped cucumbers, herbs, raisins, and toasted walnuts. Season with salt and sumac. Cover and chill for about one hour.
When ready, divide chilled cucumber soup into four serving bowls. Sprinkle more sumac on top and add a few cucumber slices to each bowl. Enjoy with your favorite toasted bread or pita.