Middle Eastern wraps make profoundly great street food, yet in Seattle they never approach the ubiquity of their tortilla’d and bunned brethren. So Yalla, a new walk-up window on East Olive Way, fills a wanting niche. Working on rounds of saj, the unleavened Palestinian flat bread, chef Taylor Cheney spreads lively, nuanced flavors. Fixed accents—olives, mint, cucumber, tomato, and arugula—meet a rotating array of fillings: za’atar, kishk (bulgur fermented with yogurt), or lahme khuruf, an ideally spiced mix of lamb and pine nuts that emphasizes the meat’s sweetness over its funk.