Sumac comes in the form of a small dark red berry, which is then ground and sometimes mixed with a little salt to ensure preservation. It is one of the basic spices of Middle Eastern cuisine. It has a tangy, even vinegar-like flavor, which is why it is often found in salads. It is also used on grilled meat (lamb, among others), vegetables, eggs, etc. Finally, it is the main ingredient, along with thyme, in this typically Middle Eastern blend, Zahtar. A spice to discover.