This refreshing salad calls for using drained yogurt, or labneh, a popular ingredient in Persian cooking and one that is easy to make at home. Line a fine-mesh strainer with two layers of cheesecloth, and spoon the yogurt into the strainer. Set the strainer in a bowl or sink with a drain. Alternatively, you can cover the yogurt with several layers of paper towels, which absorb the excess liquid in the yogurt, and place the bowl in a larger container or sink to catch the drips. For a thicker yogurt, change the towels often, and repeat for several hours. When ready, the drained yogurt will have the consistency of cream cheese. Already-drained yogurt, Persian cucumbers and edible organic rose petals are sold at Middle Eastern markets. Use only fresh rose petals. Combining the raisins with the rose petals imparts a rose fragrance to the raisins. Note: The recipe analysis does not include the bread.