This classic French Onion Soup is a game-changer for your dinner table. With perfectly caramelized onions swimming in rich beef broth and topped with crusty bread and melted cheese, it’s the ultimate comfort food that feels fancy but is surprisingly manageable to make at home. The slow-cooked onions create an incredible depth of flavor that will make you feel like you’re dining in a Parisian bistro!
Why You’ll Love This Recipe
- Restaurant-Quality at Home: This soup rivals anything you’d find at a fancy French restaurant, but you control exactly what goes into it.
- Impressive Yet Approachable: While it takes some time, each step is simple. Most of the cooking is hands-off, letting you multitask around the kitchen.
- Deeply Satisfying: The combination of sweet caramelized onions, savory broth, and gooey melted cheese creates a perfectly balanced flavor explosion.
- Great for Entertaining: There’s something theatrical about bringing bubbling, cheese-topped soup bowls to the table that always impresses guests.
Ingredients You’ll Need
- Yellow onions: The star of the show! They transform from sharp and pungent to sweet and mellow as they caramelize, creating the soup’s signature flavor base.
- Butter: Adds richness and helps the onions caramelize beautifully without burning.
- Flour: Just a small amount creates the perfect thickness without making the soup starchy or heavy.
- Sherry or white wine: Deglazes the pan and adds wonderful depth and acidity that balances the sweetness of the onions.
- Beef broth: The foundation of your soup – using high-quality broth makes a massive difference in the final flavor.
- Better Than Bouillon Beef Base: Intensifies the beefy flavor without making the soup too salty.
- Vegetable aromatics (carrots, onion, celery, garlic): These create a flavor-packed broth that adds complexity.
- Horseradish: A secret ingredient that adds a subtle kick and enhances the other flavors without making the soup spicy.
- Fresh herbs (thyme, rosemary, bay leaves): Infuse the broth with classic French flavors.
- French bread: Provides the perfect crispy yet sturdy platform for the cheese topping.
- Cheese trio (Gruyere, Parmesan, Swiss): Each brings a different flavor profile – nutty, salty, and mild – creating the perfect golden, gooey crown.
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
Make It Vegetarian
Substitute vegetable broth for beef broth and add a tablespoon of soy sauce or miso paste for depth. You’ll get a surprisingly rich flavor that even meat-lovers will enjoy.
Wine Options
No sherry? Try a dry white wine like Sauvignon Blanc or even a light red like Pinot Noir. Each brings a different but delicious character to your soup.
Cheese Alternatives
If you can’t find Gruyere, try Emmental, Comte, or even a sharp white cheddar. The key is using at least one cheese that melts beautifully.
Add a Hearty Twist
For a more substantial meal, add sautéed mushrooms or small pieces of cooked beef to the soup before adding the bread and cheese topping.
How to Make French Onion Soup
Step 1: Caramelize the Onions
Thinly slice your onions (about 8 cups total). In a large, high-sided stainless steel pan, melt the butter over medium heat. Add all the onions at once, sprinkle with salt and cayenne pepper. Cook for about 10 minutes until transparent, then reduce heat to medium-low. Continue cooking for about 90 minutes, stirring occasionally, until the onions transform to a deep golden color. Be patient – this is where the magic happens!
Step 2: Prepare the Broth
While the onions are caramelizing, combine beef broth, water, and Better Than Bouillon in a large Dutch oven over high heat. Add the roughly chopped carrots, onion, celery, smashed garlic, horseradish, herbs, bay leaves, and peppercorns. Bring to a boil, then reduce to a low simmer. Cover with a vented lid and let it bubble gently while your onions caramelize.
Step 3: Combine and Finish the Soup
When the onions are beautifully caramelized, sprinkle them with flour and stir for 1-2 minutes. Add the sherry or wine, increase heat to medium, and scrape up all those flavorful browned bits from the pan. Add lemon juice and stir until liquid is mostly absorbed.
Strain your broth and discard the vegetables. Add the caramelized onions to the strained broth, stir well, and taste. Adjust seasonings as needed.
Step 4: Prepare the Cheesy Topping
Preheat your oven to 350°F. Slice the French bread into 1-inch pieces and toast on a baking sheet for about 10 minutes, flip, and toast 5 more minutes until crisp on both sides. Grate the Gruyere and Parmesan cheeses.
Step 5: Assemble and Broil
Sprinkle a bit of both Gruyere and Parmesan in the bottom of oven-safe soup bowls. Ladle in the hot soup, place a toasted bread slice on top, and sprinkle with more grated cheese. Finish with a slice of Swiss cheese. Broil on high for 2-4 minutes until the cheese is bubbly and spotty brown.
Pro Tips for Making the Recipe
- Be Patient with Caramelization: This is the foundation of great French onion soup. Don’t rush it or crank up the heat—slow and steady wins the race for perfectly sweet onions without bitterness.
- Use a Wide, Heavy Pan: This provides more surface area for evaporation and even heat distribution, helping your onions caramelize more evenly.
- Layer Your Cheese: Putting some cheese at the bottom of the bowl before adding soup creates pockets of melty goodness throughout the bowl, not just on top.
- Taste as You Go: This is especially important when adjusting the final soup. The depth of flavor can vary based on your broth and how caramelized your onions get.
- Prep Ahead: You can caramelize the onions up to 3 days ahead and keep them refrigerated, making this soup much quicker to put together on serving day.
How to Serve
French Onion Soup is a meal in itself, but if you want to create a complete French bistro experience, consider these pairings:
Complete Meal Ideas:
Serve with a simple green salad dressed with a light vinaigrette to cut through the richness of the soup.
Wine Pairing:
A medium-bodied red wine like Beaujolais or Pinot Noir complements the sweet onions and rich broth perfectly.
Garnishes:
Fresh chives and a few cracks of black pepper add a bright finish to each bowl.
Make Ahead and Storage
Storing Leftovers
Store the soup (without bread and cheese) in an airtight container in the refrigerator for 4-5 days. The flavor actually improves after a day as the ingredients meld together.
Freezing
This soup freezes beautifully! Portion it into freezer-safe containers without the bread and cheese toppings and freeze for up to 3 months. This is a great option for meal prep.
Reheating
Thaw overnight in the refrigerator if frozen. Reheat the soup gently on the stovetop until hot, then proceed with adding the bread and cheese topping before broiling.
FAQs
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Why isn’t my soup as dark as restaurant versions?
The color comes primarily from well-caramelized onions and quality beef broth. Patience with the onions is key—they should be a deep golden brown (but not burned). Some restaurants add kitchen bouquet or soy sauce for color, which you can try if desired.
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Can I make this in a slow cooker or Instant Pot?
You can, but the onions won’t caramelize the same way. For best results, caramelize the onions on the stovetop, then transfer to a slow cooker with the broth ingredients to simmer. The Instant Pot works well for the broth portion but not for properly caramelizing onions.
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What if I don’t have oven-safe soup bowls?
No problem! Toast the bread with cheese on top under the broiler separately, then float these cheesy toasts on your soup bowls. You’ll get the same flavors without needing special bowls.
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Why add horseradish? I’ve never seen that in French onion soup before.
Horseradish provides a subtle background note that enhances the beef flavor without adding detectable spiciness. It’s a secret ingredient that adds complexity, but you can absolutely omit it if you prefer.
Final Thoughts
This French Onion Soup takes a bit of time, but it’s mostly hands-off and the result is absolutely worth it. There’s something magical about breaking through that cheesy crust into the rich, oniony broth below. Whether you’re cooking for a special occasion or just treating yourself, this soup delivers restaurant-quality comfort that will leave everyone asking for seconds. Give it a try—I promise you’ll be amazed by what you can create in your own kitchen!
Print
French Onion Soup Recipe
- Prep Time: 10 minutes
- Cook Time: 1 hour 40 minutes
- Total Time: 1 hour 50 minutes
- Yield: 7 servings 1x
- Category: Main-course
- Method: Stovetop
- Cuisine: French
- Diet: Vegetarian
Description
French Onion Soup is a classic French recipe featuring deeply caramelized onions simmered in a rich, flavorful homemade beef broth. Topped with crisp toasted French bread and a melty combination of Gruyere, Swiss, and Parmesan cheeses, this soup is broiled to perfection for a comforting and savory meal.
Ingredients
For the Onion Soup Base
- 4 large yellow onions (about 3 pounds), thinly sliced
- 4 tablespoons butter (half stick)
- 1 tablespoon kosher salt (use less if using table salt)
- 1/4 teaspoon cayenne pepper (optional)
- 2 tablespoons all purpose flour
- 1/2 cup sherry wine or white wine
- 1 tablespoon fresh lemon juice (about half a lemon)
For the Broth
- 8 cups high quality beef broth
- 2 cups water
- 1 tablespoon Better Than Bouillon Beef Base
- 3 carrots, peeled and roughly chopped
- 1 yellow onion, roughly chopped
- 2 stalks celery, roughly chopped
- 6 large cloves garlic, smashed
- 1 teaspoon prepared horseradish (or more, to taste)
- 3 sprigs fresh thyme (or 1/2 teaspoon dried thyme)
- 3 small sprigs fresh rosemary (or 1/2 teaspoon dried rosemary)
- 3 bay leaves
- 15 peppercorns (about 1/2 teaspoon)
For the Topping
- 1 (1-pound) loaf of French bread, sliced into 1-inch thick slices
- 1 cup gruyere cheese, freshly grated
- 1 cup parmesan cheese, freshly grated
- 8 ounces Swiss cheese, sliced
Garnish (optional)
- Freshly chopped chives
- Freshly cracked black pepper
Instructions
- Slice the Onions – Thinly slice about 4 large yellow onions (about 3 pounds) to yield about 8 cups. This ensures even caramelization and makes the soup easier to eat.
- Caramelize the Onions – In a 12-inch, high-sided stainless steel pan, melt 4 tablespoons butter over medium heat. Add the onions, sprinkle with 1 tablespoon kosher salt, and add the cayenne pepper. Cook over medium heat for 10 minutes until onions are translucent, stirring occasionally.
- Slow Caramelization – Reduce heat to medium-low, and continue to cook the onions for about 90 minutes, stirring every 10-20 minutes, until they are deeply golden and sweet, with no oniony ‘bite’, ensuring not to scorch the edges.
- Prepare the Broth – In a large Dutch oven or stockpot over high heat, combine 8 cups beef broth, 2 cups water, and 1 tablespoon Better Than Bouillon Beef Base. Add carrots, onion, celery, garlic, horseradish, thyme, rosemary, bay leaves, and peppercorns. Bring to a boil, then reduce heat and simmer, covered (with steam vent), while onions caramelize.
- Strain the Broth – Once the onions are caramelized and the broth has simmered (about 90 minutes), strain the broth through a colander, discard the solids (veggies and herbs), and return the broth to the pot to keep it warm.
- Add Flour and Deglaze – Sprinkle the caramelized onions with flour, stirring and cooking for 1-2 minutes to remove any raw flour taste. Add sherry or white wine, increase heat to medium, and deglaze the pan, scraping up all browned bits. Add lemon juice and continue to cook until most liquid is absorbed.
- Combine Onions and Broth – Transfer the onions and any pan juices to the warm broth. Stir well, taste and adjust seasoning, adding more salt, horseradish, or herbs as needed.
- Prepare the Bread – Preheat oven to 350°F. Slice French bread into 1-inch slices. Arrange slices in a single layer on a baking sheet and toast in the oven for 10 minutes. Flip and toast another 5 minutes until both sides are crisp. Optionally, butter the slices before toasting for extra richness.
- Assemble the Soup – Grate Gruyere and Parmesan cheese. Place about 1/2 tablespoon of each cheese in the bottom of 7 oven-safe bowls. Ladle soup into bowls, top each with a toasted bread slice, sprinkle with more Gruyere and Parmesan, and top with a slice of Swiss cheese.
- Broil and Serve – Place bowls on a baking sheet and transfer to the oven on a rack set in the upper third. Broil on high for 2–4 minutes, until cheese is melted and browned in spots. Remove carefully, garnish with chives and black pepper, and serve hot. Warn guests that bowls will be very hot.
Notes
- For a vegetarian version, substitute beef broth with a rich vegetable broth.
- Butter each bread slice before toasting for extra flavor.
- Keep bread and cheese separate from soup for storage and when freezing.
- Fresh herbs provide superior flavor but dried herbs can be used in a pinch.
- Broil soup in oven-safe bowls only; take care as bowls become very hot during broiling.
- Soup stores well in the refrigerator for 4-5 days or can be frozen (leave bread and cheese out until serving).
Nutrition
- Serving Size: 1 bowl (about 2 cups)
- Calories: 410
- Sugar: 8 g
- Sodium: 1450 mg
- Fat: 22 g
- Saturated Fat: 12 g
- Unsaturated Fat: 8 g
- Trans Fat: 0.5 g
- Carbohydrates: 35 g
- Fiber: 4 g
- Protein: 19 g
- Cholesterol: 55 mg
