The Levantine spice blend containing sumac, sesame, and dried herbs is called za'atar.
Za'atar usually combines dried za'atar herb or related wild oregano, sumac, toasted sesame seeds, and salt. Recipes vary by country and household, so the exact herb mixture is not completely standardized. Some commercial blends include marjoram, thyme, or cumin.
Across the Levant, za'atar is mixed with olive oil and spread over flatbread before baking. It is also sprinkled over labneh, salads, eggs, and vegetables. The sumac contributes a tart flavor, while sesame adds nuttiness.
The word can refer both to the seasoning blend and to aromatic plants in the Origanum, Thymbra, and related genera. This creates a common mix-up: za'atar is not one single universally fixed recipe.