Learn how to recreate restaurant-quality French Onion Soup in your own kitchen.

This iconic French dish combines the sweet depth of caramelized onions with a savory beef broth, all topped with a slice of crusty bread and golden, bubbling melted cheese.

The signature "gratinée" step, where cheese is melted to perfection on top, is what makes this soup truly special. I'll guide you through each stage of the process and offer tips for making it on the stovetop, slow cooker, or Instant Pot.

1. Caramelizing the Onions

Don't shed tears over these onions—they're the heart of your French onion soup! Choose sweeter varieties like Walla Walla or Vidalia onions for the best flavor, or mix in some regular yellow onions. If yellow onions are all you have, enhance the sweetness with a splash of balsamic vinegar or a pinch of brown sugar after caramelizing. Start by cutting your onions in half and slicing them thinly.

• Tip: When caramelizing onions, low and slow is the way to go. Make sure to take your time and cook the onions over low heat, so that the natural sugars caramelize instead of burn. If you're doing it right, this should take 30 to 40 minutes. Make sure to stir the onions often and scrape the pot with a wooden spoon to keep all of those tasty browned bits on the bottom from burning.
• Tip: When you're combining the onions and broth, pour a bit of broth into the hot onion pan and scrape up the browned bits to add to the soup.

2. Preparing the Broth

Beef broth is the key to a rich, savory French onion soup, perfectly balancing the sweetness of the caramelized onions. For a lighter version, swap the beef stock with chicken or vegetable broth. You can either make your own beef bone or chicken broth, use a concentrated version mixed with water, or grab a box of pre-made stock. To enhance store-bought broth, simmer it with fresh herbs, a dollop of miso paste, whole peppercorns, garlic cloves, or even a Parmesan rind. Just remember to strain it before adding to your soup!

• Tip: Adding a splash of wine gives the soup a nice "pop" from the acid. If you don't have a bottle of red on hand, you can use white wine, red or white wine vinegar, cognac, sherry, or even a splash of brandy!
• Tip: Want to add even more flavor? Add a few fresh sprigs of thyme or rosemary, or a few bay leaves to your simmering soup.

3. The Bread Layer

Slices of French baguette create the perfect base for the classic French onion soup gratinée topping: crispy bread and melted cheese. If your bread is a bit stale, that's even better! A slightly toasted or day-old slice will soak up just the right amount of broth without turning into mush by the time your soup is ready to serve.

• Tip: No baguette on hand? Reach for other crusty counterparts, like Italian bread, stale croissants, or even store-bought or homemade croutons. Just make sure to cut them to fit snugly in your bowl.

4. Cheese

Cheese is the essential finishing touch for French onion soup gratinée. Gruyère is the traditional choice, with its nutty, mild flavor that resembles Swiss cheese. If you can't find Gruyère, Swiss cheese works just as well. But don't feel limited—feel free to get creative and use other cheeses you love, or have on hand. Parmesan, mozzarella (shredded or sliced), Brie, Havarti, and Gouda are all excellent alternatives, either on their own or mixed together.

• Tip: Slice or shred? Some like the simplicity of a slice of cheese on top of their soup. It creates a nice "lid" to the dish and doesn't make much of a mess. However, if you're looking for some authenticity (and amazing flavor), choose grated cheese. It will fall into the soup and melt, resulting in delicious melty strands of cheesy-goodness with every bite.
• Tip: For easy serving, place individual oven-proof bowls on a baking sheet and fill with soup. Top with toasted bread and shredded or slice cheese. Slide the baking sheet under the broiler for 3 to 5 minutes, just until the cheese is melted and bubbly, with a toasted golden crust.

5 Ways to Make French Onion Soup

1. Slow Cooker French Onion Soup: Let the caramelized onions simmer all day in broth, and finish the soup with a classic gratinée under the broiler.
2. French Onion Soup Gratinée: A stovetop version made with a mix of chicken and beef broth.
3. Instant Pot French Onion Soup: Quick and convenient, but you'll need to give the onions a little extra time to caramelize for that signature depth of flavor.
4. Vegan French Onion Soup: A plant-based twist on the classic recipe with vegan-friendly ingredients.
5. French Onion Soup I: A stovetop version with a touch of flour to slightly thicken the broth.

Discover more delicious French Onion Soup recipes to try.