Name: Classic French Onion Soup Recipe
Prep time: 15 min
Cook time: 1 h
Total time: 1 h 15 min
Cuisine: French
Ingredients: 2 tablespoons olive oil; 6 medium yellow onions, sliced; 2 tablespoons butter; 1 tablespoon minced garlic; 8 cups beef broth; 1/4 cup dry sherry (optional); 1 teaspoon dried thyme; 1 teaspoon salt or to taste; 1/2 teaspoon black pepper or to taste; 8 slices French baguette; 2 tablespoons olive oil; 4 slices Gruyère cheese or provolone; 2 tablespoons grated Parmesan cheese

There’s something incredibly cozy about a bubbling pot of deeply caramelized onions, savory broth, and melted cheese on crusty bread. This Classic French Onion Soup Recipe really delivers that soul-warming comfort in a bowl—perfect for chilly evenings or anytime you want a little French flair at home.

This image shows two white mugs with handles filled with French onion soup. Each mug has a dark brown onion broth as the bottom layer. On top of the broth are two toasted brown bread slices covered by melted golden cheese that is bubbly and slightly browned. A small green herb branch sits on top of the cheese in each mug, adding a fresh touch. The mugs are placed on a white marbled surface with some small scattered herb leaves around. The scene has a cozy and warm feeling. photo taken with an iphone --ar 2:3 --v 7

Jump to:

Why You'll Love This Recipe
Ingredients & Why They Work
Make It Your Way
Step-by-Step: How I Make Classic French Onion Soup Recipe
Top Tip
How to Serve Classic French Onion Soup Recipe
Make Ahead and Storage
Frequently Asked Questions:
Final Thoughts
Classic French Onion Soup Recipe

Why You'll Love This Recipe

I still remember the first time I made this Classic French Onion Soup Recipe from scratch — the smell alone had my whole kitchen feeling like a little café in Paris. It’s worth the slow caramelizing process because that’s where all the magic happens. I can’t wait for you to enjoy it just as much as I do!

Deep, rich flavor: Slow-caramelized onions bring a natural sweetness that makes this soup truly unforgettable.
Simple ingredients: You don’t need anything fancy—just good broth, fresh onions, and quality cheese.
Comforting texture: Crispy toasted baguette slices topped with bubbling, melty cheese is the ultimate cozy meal.
Perfect anytime dish: Whether for a weeknight dinner or impressing guests, this soup never disappoints.

The image shows a white bowl filled with golden brown French onion soup topped with melted cheese that looks bubbly and slightly crispy. On top of the cheese, there is a layer of caramelized onions that are light golden and shiny. A spoon is lifting a portion of the cheese and onions from the bowl, showing the texture of the melted cheese stretching and the soft onions underneath. There is another white bowl with the same soup blurred in the background. The bowls sit on a white marbled surface, giving a clean and bright look. A small green herb garnish is placed on top of the soup, adding a touch of color photo taken with an iphone --ar 2:3 --v 7

Ingredients & Why They Work

Each ingredient in this Classic French Onion Soup Recipe plays a starring role. From the onions that caramelize to perfection, to the broth that gently simmers all the flavors together, it’s about balance and patience. Here’s the scoop on the essentials before you shop:

Flat lay of a medium pile of thinly sliced yellow onions, a small pool of golden olive oil in a shallow dish, a few pats of soft butter on a wooden board, a small bowl with minced garlic, a large bowl filled with rich dark beef broth, a small glass with amber dry sherry, a tiny heap of dried thyme, scattered coarse salt and black peppercorns, several slices of crusty French baguette brushed with olive oil, thin slices of Gruyère cheese, and a small mound of grated Parmesan cheese placed on a white marble surface, photo taken with an iphone --ar 2:3 --v 7

Yellow onions: They caramelize beautifully thanks to their natural sugars—don’t skip slow cooking here for that golden richness.
Olive oil & butter: A combo that helps cook the onions evenly and adds a nice depth without overpowering the flavor.
Garlic: Just a touch for aroma, making each spoonful more fragrant without stealing the show.
Beef broth: Gives the soup its meaty, savory backbone—homemade or store-bought both work, but quality matters.
Dry sherry (optional): Adds complexity and a hint of sweetness; I like it but it’s not a dealbreaker if you don’t have it on hand.
Dried thyme: A fragrant herb that pairs perfectly with onions and beef broth.
French baguette: Toasted until golden for that essential crispy base to hold the cheese topping.
Gruyère cheese: The star of the topping—melts beautifully and provides a nutty, buttery flavor.
Parmesan cheese: Sprinkled on top for extra sharpness and to create a lovely crust when broiled.

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Note: You'll find the complete list of ingredients, along with their exact measurements, in the printable recipe card at the bottom of this post.

Make It Your Way

I love tweaking this Classic French Onion Soup Recipe to suit my mood or what’s in the pantry. You can easily swap ingredients or add little extras to make it yours.

Variation: Sometimes I swap the beef broth for vegetable broth to make it a bit lighter or vegetarian-friendly—and it still tastes incredible.
Cheese options: If Gruyère isn’t available, provolone or even a sharp Swiss cheese work well to get that gooey topping.
Wine swap: If you don’t have dry sherry, a splash of dry white wine or even a little brandy adds a lovely touch.
Extra herbs: Adding fresh thyme or bay leaves while simmering adds a fragrant layer that makes each spoonful inviting.

Step-by-Step: How I Make Classic French Onion Soup Recipe

Step 1: Slowly caramelize the onions

Start by heating olive oil in a large pot over medium-high heat, then toss in your sliced yellow onions. Stir occasionally until they start to soften—about 5 to 7 minutes. Then, reduce the heat to medium-low and take your time: stir every few minutes for 15 to 25 more minutes until the onions turn a deep golden-brown and smell rich and sweet. This slow caramelization is the secret to deep flavor, so resist the urge to rush it or crank up the heat.

Step 2: Add butter and garlic for richness

Once the onions are beautifully caramelized, stir in butter and minced garlic. Let them cook together for 2 minutes until the butter melts and the garlic becomes lovely and fragrant. This step adds an extra layer of richness and warmth that I adore.

Step 3: Simmer with broth and seasonings

Pour in your beef broth and optional dry sherry, then season with dried thyme, salt, and black pepper. Bring everything to a gentle simmer, then drop the heat to medium-low and let it bubble away for 20 to 30 minutes. This allows the flavors to marry beautifully. Meanwhile, prep your toasted baguette slices for the topping.

Step 4: Toast the baguette slices

Brush baguette slices with olive oil on both sides, then arrange them on a baking sheet. Broil each side for 2-3 minutes until golden and crisp but watch carefully to avoid burning. These toasty slices are the perfect base for your melty cheese topping and add satisfying crunch.

Step 5: Assemble and broil to cheesy perfection

Ladle the hot soup into oven-safe bowls placed on a baking sheet. Place two toasted baguette slices atop each serving, then add a slice of Gruyère and a sprinkle of Parmesan cheese. Pop the whole tray under your broiler for 2 to 3 minutes, or until the cheese bubbles and turns golden brown. Serve immediately to enjoy that irresistible gooey finish.

Top Tip

From my years of making this Classic French Onion Soup Recipe, a few little things have made all the difference in the final dish. These tips helped me avoid common pitfalls and get that deeply flavorful, perfectly melty soup every time.

Patience with onions: Don’t rush the caramelization—low and slow is your best friend for flavor.
Watch your broiler: Cheese goes from perfect to burnt fast; keep a close eye and don’t wander off.
Use oven-safe bowls: This makes assembling and broiling much easier and safer.
Season gradually: Taste as you go before adding all the salt, especially if your broth is salty already.

How to Serve Classic French Onion Soup Recipe

Garnishes

I keep garnishes simple because the soup and cheese are the stars here. A little fresh thyme sprinkled on top adds a lovely fresh touch. Sometimes I add a tiny drizzle of truffle oil if I’m feeling fancy—it complements the caramelized onions beautifully without overpowering them.

Side Dishes

I like to keep it light with this soup—think a simple mixed green salad with a lemon vinaigrette or roasted seasonal veggies on the side. A crisp white wine or dry cider pairs wonderfully if you want to elevate your meal.

Creative Ways to Present

For dinner parties, I love serving this Classic French Onion Soup Recipe in mini cast-iron bowls or rustic crocks. Setting soup bowls on a wooden board with a sprig of herbs and a few baguette crisps on the side turns the humble soup into a chic experience that guests love.

Make Ahead and Storage

Storing Leftovers

I usually store leftover soup separately from the toasted baguettes and cheese topping in airtight containers in the fridge. The soup keeps wonderfully for up to 4 days, but the toasted bread is best fresh for the full crisp-cheesy experience.

Freezing

Freezing soup works great—just skip the bread and cheese. I freeze the soup in portion-sized containers and thaw it slowly in the fridge before reheating gently on the stove. The flavor holds up well, making it an easy make-ahead meal for busy days.

Reheating

Reheat the soup on the stovetop over low-medium heat, stirring occasionally until warmed through to avoid scorching. Then toast fresh baguette slices and melt your cheese topping just before serving—this keeps everything tasting fresh and indulgently melty.

Frequently Asked Questions:

Can I make Classic French Onion Soup Recipe vegetarian?

Absolutely! Simply swap out the beef broth for a rich vegetable broth and skip the dry sherry or replace with a splash of white wine. The slow caramelized onions still provide deep flavor.

What’s the best cheese for French onion soup?

Gruyère is classic due to its nutty flavor and excellent melting quality. However, provolone or Swiss cheese are great alternatives if you can’t find Gruyère. Adding Parmesan on top enhances the crust.

How long does it take to caramelize onions for this soup?

It usually takes about 20 to 30 minutes on medium-low heat to achieve deep golden brown color and sweet flavor. Stir every few minutes to prevent burning and encourage even cooking.

Can I prepare this soup ahead of time?

Yes! You can make the soup a day ahead and refrigerate it. Reheat gently on the stove and prepare fresh toasted bread and cheese topping just before serving for best texture and flavor.

Final Thoughts

This Classic French Onion Soup Recipe has become one of those dishes I turn to whenever I want something that’s both elegant and comforting. I love how it transforms just a handful of simple ingredients into a deeply flavored, melt-in-your-mouth experience. You’ll find the process relaxing and the results rewarding—so give it a try, and I’m sure it’ll become a favorite in your kitchen, just like it is in mine.