Cold Yogurt Soup with Cucumber, Herbs, and Rose Petals

Unlike the boldly flavored cacik, the Turkish yogurt-cucumber-garlic soup common throughout the Mediterranean and an ancestor of tzatziki, this older, hauntingly aromatic Persian soup has no garlic. Adapted from a recipe by Iranian-American chef Hoss Zaré, this dish combines nuts and raisins with dill, mint, chives, and dried rose petals, all suspended in yogurt, creating a delicate, refreshing, and crunchy soup. I use almonds instead of the walnuts the original recipe calls f