The Step You Shouldn't Skip When Making French Onion Soup

There is quite literally nothing better on a cold autumn day than a steaming bowl of French onion soup. Unless, of course, you have a deep and unyielding hatred of onions and melted cheese, and if that's the case, what is wrong with you?

Anyways, the soup, despite its massive modern popularity, is pretty ancient in origin — at least, basic onion soup is. According to Food History, the first onion soup recipe is recorded in the 14th-century cookbook "Viandier." This recipe describes onions cooked in butter and then garnished with a pea puree and verjus (the juice from unripe grapes). It was only in the 18th century in Paris that onion soup recipes began calling for the use of beef broth, caramelized onions, bread, and cheese. Eventually it became popular as a hangover cure and a simultaneous way to mask one's drunken stench, thanks to the rich smell of the Gruyère cheese. 

Cheese and onion lovers everywhere are obsessed with making a refined and rich French onion soup experience packed with flavor and warmth, and one of the most important ingredients to complete the dish (besides the vegetables) is the cheesy topping.

Let's be honest. If you ordered a bowl of French onion soup at a restaurant and they brought out the broth and bread but skipped the cheese, you'd be pretty upset. French onion soup is not complete without cheese, specifically, Gruyère. Without this melted goodness on top, the soup lacks some luster. If you want to make the best French onion soup possible, Kitchn insists that you absolutely must top your soup with crusty bread like sourdough and pile on as much Gruyère cheese as you can before placing your bowl under the broiler to bubble and melt.

Why is Gruyère so important to French onion soup? It's all in the quality. Castello Cheese tells us that this cow's milk cheese is full-bodied and nutty. The Swiss-made cheese can take upward of 18 months to fully mature and is extremely meltable, which makes it perfect for French onion soup.

But if for some reason you don't have some good ol' Gruyère hiding in your cheese drawer or just don't find it appealing, The Pioneer Woman gives us several substitutions, the first of which is Emmental. Emmental tends to melt like Gruyère but has larger holes and a buttery flavor. For those of us on a budget, American Swiss cheese is similar to Emmental cheese. Finally, Comté has a similar flavor to Gruyère, and when young can be easily melted on top of your soup.