"French onion soup is one of my all time favourite soups. The unwaveringly delicious flavour of caramelized onions, rich beef stock and ooey gooey gruyere cheese makes it easy to understand why this classic has stood the test of time. I could easily eat it every night and so keeping that in mind I came up with this five ingredient family favourite. The end result is a casserole style dish that embodies all the qualities of a delicious French onion soup!"