Soupe à l’oignon

This is a classic French soup made with onions and beef stock, usually topped with croutons and melted cheese. This was traditionally a peasant dish dating back to Roman times, though the current version dates from the 18th century.

Caramelizing the onions is the first step in making Soupe à l’oignon. This step can take a few hours, depending on the type of onions and the amount of heat used, before the onions reach the desired consistency and color. When the onions are fully caramelized, liquid — usually water or beef broth — is added, and once everything is brought to a heavy boil, the heat is turned down, and the soup is left to simmer.

Flour can be added to the broth before or after the liquid is added to thicken it. Dry bread or toasted croutons are sprinkled on top of the finished soup in individual crock pots. For the gratinated version, a generous amount of grated cheese — preferably Gruyère or Comté — is spread over the bread and placed under the broiler to melt the cheese and create a beautiful golden crust.