Tart Purslane-Coriander Broth with Lemony Fish

No need for stock making here, thanks to bottled Chinese oyster sauce, which gives depth to the briefly simmered aromatics. Widely available, the sweetly smoky seasoning is at its best when made of few ingredients— oyster being the first. The purslane stems lend a little body and slickness to the broth. The leaves add decided crunch and color—but will turn gray if allowed to cook: Just stir into the hot soup to wilt a bit. Find cilantro with its roots attached. They scent the soup more asse