French Onion Soup is the kind of dish that practically gives you a warm hug from the inside out. Melted Gruyère, golden baguette slices, and sweet, deeply caramelized onions all come together in a savory broth that’s pure comfort in a bowl. Whether you’re hoping to impress guests with a classic bistro treat or just craving an extra-special weeknight meal, this iconic French Onion Soup always delivers layers of big flavor in each spoonful.
Ingredients You’ll Need
The beauty of this French Onion Soup lies in its humble, carefully chosen ingredients. Each component plays a crucial role, from the depth of broths to the sweetness of onions and, of course, the oozy cheese topping—it’s simple, but every detail matters for that perfect restaurant-style flavor.
- 4 large yellow onions, thinly sliced: Their natural sweetness turns into the backbone of this soup as they caramelize slowly.
- 3 tablespoons unsalted butter: Adds richness and helps the onions turn beautifully golden during caramelization.
- 1 tablespoon olive oil: Prevents the butter from burning and lends another note of flavor to the sautéed onions.
- 1 teaspoon sugar: Just enough to enhance the natural sugars in the onions and encourage caramelization.
- 1 teaspoon salt: Draws out the onion juices and balances the sweetness.
- 4 cups beef broth: Provides that hearty, classic foundation with robust, savory notes.
- 2 cups chicken broth: Lightens up the base a bit and adds extra depth to the final flavor.
- 1/2 cup dry white wine: A splash of acidity to balance the sweet and savory, while deglazing the pan for more flavor.
- 2 tablespoons all-purpose flour: Thickens up the soup so it hugs your spoon in all the right ways.
- 1 teaspoon fresh thyme leaves (or 1/2 teaspoon dried thyme): Infuses a delicate herbal note that completely transforms the broth.
- 1 bay leaf: Adds a subtle earthiness and extra aroma during simmering.
- Salt and pepper to taste: Final seasoning to bring all the flavors into harmony.
- 1 baguette, sliced: The essential base for your cheesy gratin topper—crusty, chewy, and made to soak up soup.
- 2 cups grated Gruyère cheese: Nutty, melty Gruyère is nonnegotiable for the ultimate French Onion Soup experience.
How to Make French Onion Soup
Step 1: Caramelize the Onions
Start by setting a large pot or Dutch oven over medium heat, then melt the butter with olive oil. Add your patiently sliced onions, sprinkle in the sugar and salt, and get comfortable—this is where the magic happens. Stir frequently and let the onions cook low and slow for 30 to 40 minutes, transforming from sharp and crisp to soft, deeply sweet, and a gorgeous golden brown. This step is what gives French Onion Soup its signature complexity, so don’t rush it!
Step 2: Add Flour and Deglaze
Once the onions are caramelized, sprinkle in the flour and stir, cooking for a minute or two to banish any raw flour taste. Next, pour in the white wine. Use your spoon to scrape up all those delicious browned bits from the bottom of the pot—these are pure flavor gold and essential to a rich French Onion Soup.
Step 3: Simmer the Soup
Add the beef broth, chicken broth, thyme, and bay leaf to the pot. Stir everything together and bring it to a gentle simmer. Let the soup bubble away uncovered for 20 to 30 minutes, infusing your kitchen with mouthwatering aromas and allowing the flavors to develop beautifully. When you’re done, fish out the bay leaf and adjust the salt and pepper until it tastes just right.
Step 4: Prepare the Baguette and Cheese
As your soup simmers, preheat your broiler. Lay out your baguette slices on a baking sheet and toast them for 1 to 2 minutes per side, just enough for a crisp bite and a golden hue. These will soon become the cheesy, irresistible crown on your French Onion Soup.
Step 5: Assemble and Broil
Ladle the soup into oven-safe bowls arranged on a baking sheet. Float a toasted baguette slice on each bowl, then pile on a generous handful of grated Gruyère. Slide the bowls under the broiler for 2 to 3 minutes—just until the cheese bubbles and turns golden brown in tempting little spots. Serve hot, and marvel at how classic French Onion Soup can make any night feel extraordinary.
How to Serve French Onion Soup
Garnishes
This soup is all about finishing touches. A last sprinkle of freshly cracked black pepper, a few thyme leaves, or even a hint of minced chives will add color and a little fresh lift right at the table. Serve piping hot, ensuring the cheese stays gloriously gooey for that perfect cheese pull.
Side Dishes
French Onion Soup is hearty enough to be a meal on its own, but it also makes an elegant starter for steak, roast chicken, or a classic green salad. Try pairing it with a crisp vinaigrette salad or roasted asparagus for a bistro-inspired dinner at home.
Creative Ways to Present
French Onion Soup looks impressive served in classic lion’s head bowls, but you can get creative—try mini ramekins for a party, or bake the soup in a hollowed out bread bowl. Want extra flair? Set the bowls on wooden boards with a side of cornichons or charcuterie.
Make Ahead and Storage
Storing Leftovers
Allow any leftover French Onion Soup to cool completely, then transfer it to an airtight container. It will keep in the fridge for up to four days. Just store the toasted bread and cheese separately to avoid sogginess.
Freezing
The soup itself, without the bread and cheese toppings, freezes beautifully. Pour cooled soup into freezer-safe containers, leaving a little room at the top for expansion. It stays fresh for up to three months—perfect for making busy nights feel special.
Reheating
Gently reheat thawed or refrigerated soup on the stovetop over low to medium heat, stirring occasionally. For the best cheese pull, toast fresh baguette slices and top with cheese just before serving—broil as usual over individual servings after the soup is hot.
FAQs
Can I make French Onion Soup vegetarian?
Absolutely! Use a high-quality vegetable broth in place of the beef and chicken broths. The flavor will shift slightly, but you’ll still achieve beautifully caramelized onions and that comforting, savory hit.
Is there a substitute for Gruyère cheese?
If you can’t find Gruyère, try Swiss cheese or Emmental for a similar nutty melt. Provolone and mozzarella also work in a pinch, though their flavor will be a bit milder.
Why do I need both beef and chicken broth?
This combination gives French Onion Soup a rich, layered flavor—beef broth adds depth while chicken broth keeps the taste balanced and not overly heavy. It’s my favorite trick for hitting the right note!
What’s the key to perfectly caramelized onions?
Patience! Cook the onions slowly over medium heat and stir often. Rushing will just brown the onions without letting their natural sugars develop—true caramelization takes at least 30 minutes but is worth every minute.
Can I prepare this dish ahead for a dinner party?
Definitely. Prepare the soup base a day or two in advance, then simply toast the bread, grate the cheese, and broil everything together right before serving for restaurant-quality results with zero stress.
Final Thoughts
Give this French Onion Soup a try and I promise it’ll become your go-to for cozy, impressive, and totally satisfying meals. There’s nothing quite like that first spoonful of melty cheese, savory broth, and sweet onion—once you taste homemade, you’ll never look back. Bon appétit!
Print
French Onion Soup Recipe
- Total Time: 1 hour 30 minutes
- Yield: 4 servings 1x
- Diet: Non-Vegetarian
Description
A comforting and classic French Onion Soup recipe that features caramelized onions, rich beef and chicken broth, white wine, and a cheesy Gruyère topping. Perfect for a cozy winter meal.
Ingredients
Onion Base:
- 4 large yellow onions, thinly sliced
- 3 tablespoons unsalted butter
- 1 tablespoon olive oil
- 1 teaspoon sugar
- 1 teaspoon salt
Soup:
- 4 cups beef broth
- 2 cups chicken broth
- 1/2 cup dry white wine
- 2 tablespoons all-purpose flour
- 1 teaspoon fresh thyme leaves (or 1/2 teaspoon dried thyme)
- 1 bay leaf
- Salt and pepper to taste
Toppings:
- 1 baguette, sliced
- 2 cups grated Gruyère cheese
Instructions
- Caramelize Onions: In a large pot, melt butter with olive oil. Add onions, sugar, and salt. Cook until golden brown, about 30-40 minutes.
- Add Flavors: Sprinkle flour over onions, stir well. Add wine, then beef broth, chicken broth, thyme, and bay leaf. Simmer for 20-30 minutes. Season with salt and pepper.
- Prepare Toppings: Toast baguette slices under broiler. Ladle soup into bowls, top with baguette and Gruyère. Broil until cheese melts.
Notes
- For extra depth, add a splash of brandy or sherry before serving.
- Use good-quality broth for best flavor.
- Prep Time: 15 minutes
- Cook Time: 1 hour 15 minutes
- Category: Soup
- Method: Stovetop, Broiling
- Cuisine: French
Nutrition
- Serving Size: 1 bowl with bread and cheese
- Calories: 480
- Sugar: 9g
- Sodium: 1180mg
- Fat: 22g
- Saturated Fat: 13g
- Unsaturated Fat: 8g
- Trans Fat: 0g
- Carbohydrates: 45g
- Fiber: 4g
- Protein: 22g
- Cholesterol: 55mg
