A far cry from the crisp-tender green beans of recent fashion, this is a classic example of the popular Ottoman-era dishes called zeytinagli, in which vegetables are cooked for a long time in olive oil, then served at room temperature so that the flavors are at their peak.
Cooks' notes:
•Beans can be made 3 days ahead and chilled, covered. Bring to room temperature before serving.
•If you can't find Turkish or Greek yogurt, use regular plain whole-milk yogurt drained in a sieve or colander lined with a double thickness of paper towels, chilled, 1 hour.