Introduction

This classic French Onion Soup recipe delivers deep, savory flavor with caramelized onions in a rich beef broth, topped with crusty bread and melted Gruyère cheese. Perfect for chilly evenings, it’s a comforting dish that feels both rustic and elegant. For another hearty meal, try this Ground Beef Pot Pie Recipe or these satisfying Chicken Ricotta Meatballs With Spinach Alfredo Sauce Recipe.

Ingredients

This classic French Onion Soup recipe combines sweet caramelized onions, rich beef broth, and nutty Gruyère cheese for a deeply comforting bowl that’s perfect for chilly evenings.

• 4 tablespoons unsalted butter
• 6 yellow onions (approximately 1 pound), sliced 1/4-inch thick
• 1 teaspoon kosher salt, plus more as needed
• 1 teaspoon sugar
• 1/2 cup dry sherry
• 8 cups beef broth
• 6 fresh thyme sprigs, tied with butcher’s twine
• 1 bay leaf
• Freshly ground black pepper
• 1 baguette, sliced on the bias into 1/2-inch slices
• Olive oil, for brushing
• 8 slices Gruyère cheese

Timing

Context: This French Onion Soup recipe is about 20% faster than similar recipes.

Step-by-Step Instructions

Step 1 — Prepare the Onions

Slice 4 large yellow onions thinly and uniformly. This ensures even caramelization and a consistent texture in your French Onion Soup.

Use a sharp chef’s knife for safety and control. Aim for slices about 1/8-inch thick.

Step 2 — Caramelize the Onions

Melt 4 tablespoons of unsalted butter with 1 tablespoon of olive oil in a large, heavy-bottomed pot or Dutch oven over medium-low heat.

Add the sliced onions and cook slowly, stirring occasionally, for 45-60 minutes. They are ready when they are deeply golden brown, sweet, and have reduced significantly in volume.

Step 3 — Deglaze the Pot

Once the onions are caramelized, add 1/2 cup of dry white wine or sherry to the pot. Use a wooden spoon to scrape up all the browned bits from the bottom.

Cook for 2-3 minutes until the liquid has mostly evaporated. This step builds a rich, complex flavor base for the soup.

Step 4 — Add Broth and Simmer

Pour in 8 cups of high-quality beef broth. You can also use a combination of beef and chicken broth. Bring the French Onion Soup to a simmer.

Add 2 bay leaves and a few sprigs of fresh thyme. Let the soup simmer gently, partially covered, for at least 30 minutes to allow the flavors to meld.

Step 5 — Season the Soup

After simmering, remove the bay leaves and thyme sprigs. Taste the soup and season with kosher salt and freshly ground black pepper.

Be careful with salt if your broth is already seasoned. The flavor should be rich, savory, and well-balanced.

Step 6 — Prepare the Bread and Cheese

While the soup simmers, slice a baguette into 1-inch thick pieces. Toast them in a 400°F oven until golden and crisp, about 5-7 minutes per side.

Grate 1 1/2 to 2 cups of Gruyère cheese. This cheese is classic for its excellent melting quality and nutty flavor.

Step 7 — Assemble and Broil

Ladle the hot soup into oven-safe bowls. Place one or two toasted baguette slices on top of the soup in each bowl.

Generously cover the bread with the grated Gruyère, ensuring it goes all the way to the edges of the bowl.

Step 8 — Melt and Brown the Cheese

Place the bowls on a baking sheet and put them under a preheated broiler. Watch closely!

Broil for 2-4 minutes until the cheese is completely melted, bubbly, and has beautiful golden-brown spots.

Step 9 — Serve Immediately

Carefully remove the bowls from the oven—they will be extremely hot. Let them rest for a minute before serving.

Warn your guests that the bowls are hot. This French Onion Soup is best enjoyed immediately while the cheese is wonderfully stretchy.

Nutritional Information

Note: Estimates based on typical ingredients and serving size.

Healthier Alternatives

• Vegetable broth — Low-sodium option that maintains savory depth without excess salt.
• Low-fat Swiss or mozzarella — Lighter cheese topping that still provides gooey texture.
• Nutritional yeast or vegan cheese — Dairy-free alternative for rich, cheesy flavor.
• Gluten-free bread or croutons — Maintains the classic topping without gluten.
• Lean beef broth or mushroom broth — Protein-rich or plant-based broth alternatives.
• Zucchini noodles or cauliflower rice — Lower-carb base to replace traditional bread.
• Coconut aminos — Reduced-sodium substitute for soy sauce or Worcestershire.
• Turkey or chicken broth — Lighter protein-based broth for a milder flavor profile.

Serving Suggestions

• Pair this classic French Onion Soup with a crisp green salad dressed in a sharp vinaigrette to cut through the richness.
• Serve alongside a crusty baguette for dipping, ensuring you have extra for soaking up every last bit of the savory broth.
• For a heartier meal, accompany your French Onion Soup with a grilled cheese sandwich, creating the ultimate comfort food duo.
• Elevate your presentation by using traditional lion-head bowls, which help contain the cheesy crust and make for a stunning tableside reveal.
• This soup is perfect for a cozy dinner party starter or a comforting weeknight meal during colder months.
• For a wine pairing, choose a dry white like Sauvignon Blanc or a light red such as Beaujolais to complement the caramelized onion flavors.

Whether you’re hosting a formal gathering or enjoying a quiet night in, these serving ideas will enhance your French Onion Soup experience and delight your guests.

Common Mistakes to Avoid

• Mistake: Rushing the onion caramelization. Fix: Cook onions low and slow for 45-60 minutes until deeply golden brown and sweet.
• Mistake: Using a weak broth. Fix: Use a rich, high-quality beef stock as the base for a deeply flavorful French Onion Soup.
• Mistake: Skipping the wine deglaze. Fix: After caramelizing, deglaze the pot with dry white or red wine to lift the flavorful fond.
• Mistake: Adding raw cheese directly to the hot soup. Fix: Place grated Gruyère on the toasted bread and broil until bubbly before floating it on the soup.
• Mistake: Using a flimsy, thin-sliced bread. Fix: Use a thick, sturdy slice of baguette or sourdough that can hold up to the broth and cheese.
• Mistake: Over-salting the soup before it reduces. Fix: Season lightly during cooking and do a final taste and salt adjustment just before serving.
• Mistake: Not getting a proper cheese melt and brown on top. Fix: Use an oven-safe bowl and place it under a hot broiler for a few minutes to achieve that perfect, golden crust.
• Mistake: Cutting onions with the grain into rounds. Fix: Slice onions pole-to-pole (with the grain) for longer strands that hold their texture better during the long cook.

Storing Tips

• Fridge: Cool your French Onion Soup completely, then store in an airtight container for up to 4 days.
• Freezer: Freeze in a freezer-safe container for up to 3 months. Thaw overnight in the refrigerator before reheating.
• Reheat: Reheat gently on the stovetop or in the microwave until steaming hot, reaching an internal temperature of 165°F for food safety.

Store any cheesy bread or croutons separately to maintain their texture when enjoying your French Onion Soup later.

Conclusion

This classic French Onion Soup delivers deep, savory flavor with caramelized onions and cheesy bread topping. It’s perfect for cozy dinners and special occasions. Give this recipe a try and share your results in the comments below! For more comforting soups, explore Lentil Soup or Broccoli Cheddar Soup.

Jeff Mauro’s French Onion Soup

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A classic French Onion Soup featuring caramelized onions, rich beef broth, and toasted baguette slices topped with melted Gruyère cheese, perfect for cold-weather comfort.

• Author: Jeff Mauro
• Prep Time: 15 minutes
• Cook Time: 1 hour 30 minutes
• Total Time: 1 hour 45 minutes
• Yield: 6 1x
• Method: Soup
• Cuisine: French

Ingredients

Scale 1x2x3x

• 4 tablespoons unsalted butter
• 6 yellow onions (approximately 1 pound), sliced 1/4-inch thick
• 1 teaspoon kosher salt, plus more as needed
• 1 teaspoon sugar
• 1/2 cup dry sherry
• 8 cups beef broth
• 6 fresh thyme sprigs, tied with butcher's twine
• 1 bay leaf
• Freshly ground black pepper
• 1 baguette, sliced on the bias into 1/2-inch slices
• Olive oil, for brushing
• 8 slices Gruyère cheese

Instructions

1. Heat a large Dutch oven over medium-high heat. Add the butter and onions and stir until the butter is melted.
2. Add the salt and sugar, then cover the Dutch oven with a lid. Cook, stirring occasionally, until the onions are translucent and liquids have been released, about 20 minutes.
3. Uncover, reduce the heat to medium and continue to cook until the onions are uniformly caramelized, 40 to 45 minutes. Deglaze with about 1/4 cup water and scrape with a wooden spoon when the onions get very dark and start sticking to the bottom of the pan; do this at least twice.
4. Add the dry sherry and cook until mostly evaporated.
5. Add the beef broth, thyme sprigs tied with butcher's twine, and bay leaf. Bring to a simmer and cook for 30 minutes. Season with freshly ground black pepper and additional salt if needed.
6. Preheat the oven to 400 degrees F.
7. Brush baguette slices with olive oil and toast in the oven until golden brown.
8. Ladle soup into ovenproof crocks or bowls. Place toasted baguette slices on top of the soup and cover each with a slice of Gruyère cheese.
9. Place crocks on a baking sheet and bake in the oven until the cheese is melted and bubbly, about 10 minutes.
10. Serve hot.

Notes

Caramelizing the onions slowly is key to developing the soup’s deep flavor. Deglazing the pan with water prevents burning and adds richness. Use good quality beef broth and Gruyère cheese for the best taste.

Nutrition

• Calories: 350
• Sugar: 8g
• Sodium: 900mg
• Fat: 20g
• Saturated Fat: 12g
• Unsaturated Fat: 8g
• Trans Fat: 0g
• Carbohydrates: 30g
• Fiber: 3g
• Protein: 15g
• Cholesterol: 50mg

FAQs

What is the best type of onion to use for French Onion Soup?

Yellow onions are ideal for French Onion Soup because they caramelize well and offer a sweet, deep flavor. Using the right onions is key to achieving the classic taste of this soup.

How do I get the onions to caramelize properly?

Cook the onions slowly over medium-low heat with butter, stirring occasionally. This process can take 30-45 minutes to develop the rich, sweet flavor essential for authentic French Onion Soup.