Mast-o Khiar (Persian Cucumber and Herb Yogurt) Yogurt, both plain and with cucumbers, is everywhere on Iranian tables — the thicker and sourer, the better. Mast-o khiar is an everyday side similar to Indian raita or Greek tzatziki, but raisins, walnuts and rose petals elevate this version of the dish, adding a host of different flavors and textures.