French onion soup, or soupe à l'oignon, is a soup built on deeply caramelized onions in a beef or chicken broth, topped with toasted bread and melted cheese (traditionally Gruyère or Comté) and often finished under a broiler. Simple onion soups go back much further, but the gratinéed, cheese-topped version associated with French cuisine today is generally linked to 18th-century France, with the exact story more legend than documented fact. The broth is usually enriched with a splash of dry white wine or sherry and seasoned with thyme, bay leaf, and garlic. It's served as a starter or light main course, and regional versions substitute shallots or leeks for onions, or swap in Parmesan or Manchego for the classic Gruyère.