Classic French Onion Soup with a Bubbly Gruyere Crust.

This classic French onion soup is loaded with sweet caramelized onions, fresh thyme and a rich broth, then topped with a crunchy homemade crouton and plenty of gooey, melted gruyere. Make it with beef or vegetable broth and serve it as a starter or a cozy dinner with a fresh salad.

It's a must-make.

This homemade French onion soup is a true classic:

• Deep, layered flavor. Sweet caramelized onions, white wine, garlic and thyme in a rich broth.
• That cheesy top. A crunchy crouton under bubbly gruyere in every bite.
• Your broth, your way. Use beef broth for the classic or vegetable broth to keep it meatless.
• Restaurant-worthy at home. Simple ingredients, just a little patience.

Let’s talk texture and flavor.

The onions cook down until they are silky, sweet and almost jammy, then simmer in a savory broth brightened with white wine and a splash of vinegar. On top, the crouton soaks up the broth while staying crisp around the edges, and the gruyere melts into a nutty, bubbly blanket.

What you'll need.

Here is what you need to make French onion soup:

• Red and yellow onions – a mix gives the best sweet, deep flavor. Sweet onions work too.
• Olive oil and unsalted butter – for slowly caramelizing the onions.
• Garlic – adds depth.
• Dry white wine – sauvignon blanc or dry vermouth both work.
• Beef or vegetable broth – bone broth is great here, or use a rich vegetable broth to keep it meatless.
• Bouillon base – beef or vegetable, for an extra savory boost.
• White wine vinegar – balances the sweetness.
• Fresh thyme – tarragon or marjoram work too.
• Gruyere cheese – nutty and melty. Swiss works too.
• French bread or baguette – for the croutons.
• Cornstarch – optional, if you like a thicker soup.

For exact ingredient quantities, please see the recipe card below!

Customize it your way.

Make this French onion soup your own:

• Herbs – swap the thyme for tarragon or marjoram.
• Onions – use all one variety, like all sweet or all red.
• Cheese – try mozzarella or add a little grated parmesan with the gruyere.
• Red wine – use a dry red for an even deeper flavor.
• Bay leaves – add a couple while the soup simmers, then remove them before serving.

Flexible dietary swaps.

Easy swaps to fit the way you eat:

• Vegetarian – use vegetable broth and vegetable bouillon.
• Gluten-free – use gluten-free bread for the croutons, or skip them.
• Lighter – use less cheese and swap the butter for olive oil.
• No wine – use extra broth with a splash more vinegar.

How to make French onion soup.

It takes a little time, but every step is simple:

How to serve it.

Serve it hot, straight from the oven:

• Garnish with fresh thyme, parsley or chives.
• Serve extra baguette slices with butter on the side.
• Pair with a crisp green salad, like a strawberry goat cheese salad or a roasted beet salad.
• Make it flex – use beef broth and beef bouillon for the classic version, or keep it meatless with a rich vegetable broth.

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