Name: Classic French Onion Soup Recipe
Prep time: 10 min
Cook time: 1 h 30 min
Total time: 1 h 40 min
Cuisine: French
Ingredients: 6 tablespoons extra-virgin olive oil; 3 pounds medium yellow onions, halved and thinly sliced; ¾ teaspoon sea salt; 1½ tablespoons balsamic vinegar; 1½ tablespoons tamari; 1½ tablespoons fresh thyme leaves; 3 garlic cloves, minced; 3 tablespoons all-purpose white flour; 1 cup dry white wine; 6 cups vegetable broth; Freshly ground black pepper, to taste; Baguette slices; Gruyère cheese, aged cheddar, and/or Parmesan cheese; Fresh thyme, for garnish; Pinch of red pepper flakes, optional

If you’ve ever craved that rich, comforting bowl of soup that warms you from the inside out, you’re in the right place. I’m thrilled to share my Classic French Onion Soup Recipe with you — this one is truly fan-freaking-tastic. Whether you’re after that golden caramelized onion flavor or the perfect ooey-gooey cheesy topping, this recipe ticks all the boxes. Trust me, once you make this, you’ll be hooked just like my family and me!

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Why You’ll Love This Recipe

Deep, rich flavor: Slow-cooking the onions brings out their natural sweetness and complex taste.
Perfectly balanced umami: Balsamic vinegar, tamari, and fresh thyme add layers of savory goodness.
Cheesy, crispy topping: Toasted baguette with melted Gruyère and cheddar takes this soup over the top (in the best way).
Great for any occasion: Whether it’s a cozy night in or impressing friends, this soup fits right in.

The image shows three white small round ceramic pots filled with a thick brown soup, each topped with a round toasted slice of bread covered by melted cheese and garnished with green herb sprigs. The pots are placed on a white marbled surface with two pot lids nearby, one opened and one closed. Around the pots, there are several slices of toasted bread, two clear glasses filled with a light yellow drink, two silver spoons, and a light blue cloth napkin. The scene is bright and clean, with a casual yet elegant feel. Photo taken with an iphone --ar 2:3 --v 7 - French Onion Soup, classic French onion soup, homemade French onion soup, caramelized onion soup, cheesy French onion soup

Ingredients You’ll Need

These ingredients might seem simple, but their combination creates that signature depth and warmth you expect from a Classic French Onion Soup Recipe. Using quality olive oil and fresh thyme really makes a difference, and picking the right cheese blend for topping is my little secret weapon.

Flat lay of a small white ceramic bowl of extra-virgin olive oil, three medium yellow onions halved and thinly sliced, a few sprigs of fresh thyme leaves, three whole garlic cloves unpeeled, a small white bowl with white all-purpose flour, a small white bowl of dry white wine, a small white bowl of vegetable broth, a small white bowl of balsamic vinegar, a small white bowl of tamari, a few pinches of sea salt in a small white bowl, a few cracks of freshly ground black pepper in a small white bowl, several slices of fresh baguette, a small pile of grated Gruyère, aged cheddar, and Parmesan cheese mixed together, and a pinch of red pepper flakes in a small white bowl—all ingredients fresh and natural, arranged symmetrically on a clean white marble surface, soft natural light, photo taken with an iPhone, professional food photography style, fresh ingredients, white ceramic bowls, no bottles, no duplicates, no utensils, no packaging --ar 2:3 --v 7 --p m7354615311229779997 - French Onion Soup, classic French onion soup, homemade French onion soup, caramelized onion soup, cheesy French onion soup

Extra-virgin olive oil: It’s the base for sautéing onions—use good quality for the best flavor.
Yellow onions: Medium-sized and thinly sliced, they caramelize beautifully over low heat.
Sea salt: Enhances the onion’s sweetness and balances flavors.
Balsamic vinegar: Adds a subtle tang that deepens the soup’s richness.
Tamari: A gluten-free soy sauce alternative that boosts umami.
Fresh thyme leaves: Gives that classic herbaceous French touch.
Garlic cloves: Minced for a gentle aromatic punch.
All-purpose white flour: Helps thicken the soup slightly, creating a luscious texture.
Dry white wine: Adds acidity and complexity—don’t skip it!
Vegetable broth: The base liquid; you can go for homemade or store-bought low sodium.
Freshly ground black pepper: For seasoning as you go.
Baguette slices: For toasting and topping—day-old bread works great.
Cheese (Gruyère, aged cheddar, Parmesan): A cheese blend melts beautifully for that classic crusty finish.
Fresh thyme (optional): A pretty and flavorful garnish.
Red pepper flakes (optional): Adds a tiny kick if you like a bit of heat.

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.

Variations

I’m all about making this Classic French Onion Soup Recipe fit your taste and lifestyle. Once you get the basics down, feel free to tweak it! I’ve played around with ingredients and toppings that made the soup my own, and I bet you’ll enjoy experimenting, too.

Meaty version: Adding a splash of beef broth or some thinly sliced cooked steak can add richness if you prefer meat-based soups.
Dairy-free option: Swap out cheese for a vegan cheese or nutritional yeast for that cheesy flavor without dairy.
Spicy twist: Toss in a pinch more red pepper flakes for a subtle heat that surprises you.
Herbal variations: Try rosemary or bay leaves instead of thyme for a different herbal kick.

How to Make Classic French Onion Soup Recipe

Step 1: Slowly Caramelize Your Onions

Heat your olive oil in a large pot or Dutch oven over medium heat. Toss in the thinly sliced onions with sea salt and a few turns of freshly ground black pepper. This step is all about patience: reduce the heat to low and let those onions soften and caramelize over about 40 minutes, stirring every few minutes so they cook evenly and don’t burn. Then, crank it up to medium heat for another 15 to 20 minutes until your onions turn a gorgeous golden brown. This slow caramelization is what gives the soup its deep, sweet flavor — don’t rush it!

Step 2: Add the Flavor Boosters

Once your onions are perfectly caramelized, stir in the balsamic vinegar, tamari, fresh thyme leaves, and minced garlic. These ingredients layer in the savory, tangy notes that make this a classic. Then sprinkle the flour over the onions, stir everything well, and cook for 2 minutes. This will create a nice base for your soup’s body.

Step 3: Deglaze and Simmer

Pour in the dry white wine, stirring and cooking for about 2 minutes or until it mostly evaporates — this deglazes the pan and adds acidity. Then, add your vegetable broth and bring everything to a simmer over medium heat. Let it cook for 30 minutes to meld all those lovely flavors together.

Step 4: Prepare the Cheesy Topping

While the soup simmers, preheat your oven to 450°F and line a baking sheet with parchment paper. Top your baguette slices with a generous mix of Gruyère, aged cheddar, and Parmesan cheese. Pop them in the oven for 8 to 10 minutes until they’re golden, toasty, and bubbling with melty cheese. This is the part that got my whole family hooked—I love the crunch and gooeyness together.

Step 5: Serve and Enjoy

Ladle the hot soup into ramekins or sturdy bowls. Crown each bowl with a toasted, cheesy baguette slice, add a sprinkle of fresh thyme, and if you’re up for it, a pinch of red pepper flakes for a tiny kick. Sit back, grab a spoon, and enjoy the cozy magic of a Classic French Onion Soup Recipe done right.

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Pro Tips for Making Classic French Onion Soup Recipe

Low and Slow Caramelization: I learned the hard way that rushing the onions over high heat ruins the flavor—keep the heat low and stir often for that perfect golden brown.
Wine Selection Matters: I usually go for a crisp dry white wine like Sauvignon Blanc; it lifts the soup without overpowering it.
Cheese Blend Magic: Mixing Gruyère with sharp cheddar balances meltiness and bold flavor—try not to skip the Parmesan for a subtle nutty note.
Avoid Soggy Bread: Toast baguette slices first, then top with cheese and bake again to keep that perfect crunch under the melted cheese.

How to Serve Classic French Onion Soup Recipe

Classic French Onion Soup Recipe - Serving

Garnishes

I love finishing this soup with fresh thyme sprigs for that pop of color and herbal brightness. A pinch of red pepper flakes is my little trick to add a gentle heat that cuts through the richness—feel free to skip if you prefer a milder flavor.

Side Dishes

This soup is a star on its own but pairs beautifully with a simple green salad dressed with Dijon vinaigrette. Crusty bread on the side (because you can never have too much bread!) or a light roasted vegetable medley also complements the meal nicely.

Creative Ways to Present

For a special occasion, I like to serve this soup in individual mini Dutch ovens or oven-safe crocks—presentation instantly feels elevated. You can also sprinkle extra cheese mixed with herbs on top before broiling briefly for a bubbly golden crust that wows guests every time.

Make Ahead and Storage

Storing Leftovers

I usually store leftover soup in airtight containers in the fridge for up to 3 days. The flavors actually deepen overnight, so it tastes even better the next day. Just keep the toasted baguette and cheese separate to avoid sogginess.

Freezing

This soup freezes very well! I portion it into freezer-safe containers without the bread topping and it keeps beautifully for up to 3 months. When thawed, just toast fresh baguette slices and add freshly melted cheese on top.

Reheating

Reheat gently on the stove over low to medium heat, stirring occasionally to prevent sticking. If the soup thickened too much, stir in a splash of broth or water to loosen it up. Add the toasted cheesy baguettes on top right before serving.

FAQs

Can I use red onions instead of yellow in this Classic French Onion Soup Recipe?

While yellow onions are preferred for their sweetness and caramelization, you can definitely use red onions if that’s what you have. Just keep in mind that red onions have a slightly sharper flavor and a different color, but the soup will still be delicious.
Is it okay to skip the wine in this recipe?

If you want to avoid alcohol, you can substitute the dry white wine with additional vegetable broth or a splash of apple cider vinegar for acidity. The wine adds complexity, but the soup will still be flavorful without it.
How do I prevent the bread from getting soggy?

To keep your baguette slices crispy under the melted cheese, toast the bread slices separately first, then add cheese and bake again. Serve immediately so the bread stays crunchy and doesn’t soak up too much liquid from the soup.
Can I make this soup vegan?

Absolutely! The recipe uses vegetable broth, so it’s easy to keep vegan. Just swap out the cheese for a plant-based meltable alternative or sprinkle nutritional yeast on top for a cheesy flavor without dairy.
How long does it take to make Classic French Onion Soup Recipe?

This recipe takes about 10 minutes to prep and roughly 1 hour and 30 minutes to cook, mostly because of the slow caramelization process. The total time is about 1 hour and 40 minutes. It’s worth every minute!

Final Thoughts

I absolutely love how this Classic French Onion Soup Recipe turns out every single time. It’s the kind of dish that feels like a warm hug on a chilly day and impresses guests without needing fancy techniques. When I first tried perfecting this, I used to struggle with getting my onions just right—but once I found the patience for slow caramelizing, everything clicked. Now, my family goes crazy for it, especially with that melty cheese topping! I’m confident you’ll enjoy making and sharing this recipe just as much as I do. Give it a try—you won’t regret it!