The Middle Eastern spice blend za'atar gives you big flavor from just one ingredient: it's a mix of thyme, sumac, salt, sesame seeds and sometimes other herbs. Look for it in the bulk-spice section of natural-foods stores, in specialty-foods stores, in the spice section of some grocery stores or online. To make your own mix: Combine 1 tsp. each ground sumac, sesame seeds and dried thyme with ¼ tsp. salt.
To oil a grill rack, oil a folded paper towel, hold it with tongs and rub it over the rack. (Do not use cooking spray on a hot grill.)