The tart leaves of the oseille (sorrel) plant are often used in dishes with river fish such as shad and pike and salmon (quiche salmon oseille is a classic), or with veal, and in soups. Many add the very young leaves to a salad. You can usually find sorrel in the fresh herb section of the supermarket refrigerator.
Avoir de l’oseille ‘to have some sorrel’ is to have plenty of money.
Image by Hans