The Turkish word türlü means ‘with variety’, and implies that you can use any kind of vegetable that’s available in summer. This is sometimes called the Turkish ratatouille, but türlü has many more ingredients than the French dish, and you can even include lamb or beef and still call it türlü.
You need to layer the ingredients in a deep pot (traditionally clay), with the slowest-cooking vegetables at the bottom, and simmer it for a long time. So yes, it’s a casserole, which is normally thought of as a winter warmer. But this version, which includes green beans and okra, is perfect served cold on the hottest day, with a side of rice pilav and yoğurt. It tastes even better the next day.