Onions are commonly chopped and used as an ingredient in various hearty warm dishes, and may also be used as a main ingredient in their own right, for example in French onion soup or onion chutney. They are versatile and can be baked, boiled, braised, grilled, fried, roasted, sautéed, or eaten raw in salads. Their layered nature makes them easy to hollow out once cooked, facilitating stuffing them, as in sogan-dolma. Onions are a staple in Indian cuisine, used as a thickening agent for curries and gravies. Onions pickled in vinegar are eaten as a snack. These are traditionally a side serving in pubs and fish and chip shops throughout the United Kingdom and the Commonwealth. Pickled onions form part of a British pub ploughman’s lunch, usually served with cheese and ale. In North America, sliced onions are battered, deep-fried, and served as onion rings.