Classic French Onion Soup

Featured in: Everyday Flour-First Dinners

This beloved bistro classic transforms humble yellow onions into something extraordinary through slow caramelization. The onions cook down until deeply golden and sweet, creating a rich, savory base that simmers with beef broth, white wine, and aromatic herbs.

The finishing touch—thick slices of crusty French bread topped with generous amounts of melted Gruyère cheese—creates the perfect contrast of textures. Serve piping hot for the ultimate comfort experience that pairs beautifully with a glass of dry white wine.

Updated on Tue, 27 Jan 2026 21:13:50 GMT
Golden French Onion Soup with deeply caramelized onions in a rich broth, topped with crusty bread and melted Gruyère cheese. Pin It
Golden French Onion Soup with deeply caramelized onions in a rich broth, topped with crusty bread and melted Gruyère cheese. | hazelflour.com

Experience the essence of a French bistro in your own kitchen with this classic French Onion Soup. This recipe features deeply caramelized onions simmered in a rich beef broth, topped with a thick slice of crusty bread and a generous layer of melted Gruyère cheese. With a total time of 1 hour and 35 minutes, it is a rewarding dish that provides ultimate comfort for any occasion.

Golden French Onion Soup with deeply caramelized onions in a rich broth, topped with crusty bread and melted Gruyère cheese. Pin It
Golden French Onion Soup with deeply caramelized onions in a rich broth, topped with crusty bread and melted Gruyère cheese. | hazelflour.com

Preparing this soup is a lesson in patience. By slowly cooking the onions in butter and olive oil for nearly 45 minutes, you unlock their natural sweetness, which forms the backbone of the broth. Whether you choose the traditional beef broth or a vegetarian alternative, the result is a sophisticated and heartwarming meal.

Ingredients

  • Onions: 6 large yellow onions (thinly sliced), 2 tablespoons unsalted butter, 1 tablespoon olive oil
  • Broth: 6 cups beef broth (or vegetable broth), 1/2 cup dry white wine (optional)
  • Flavorings: 2 cloves garlic (minced), 1 teaspoon sugar, 1 teaspoon salt, 1/2 teaspoon freshly ground black pepper, 2 sprigs fresh thyme (or 1/2 teaspoon dried), 1 bay leaf
  • Topping: 4 slices crusty French bread (1 inch thick), 2 cups grated Gruyère cheese
Product image
Create smooth frozen drinks, slushies, and frappés for desserts and parties using juices, coffee, or wine.
Check price on Amazon

Instructions

Step 1
In a large heavy-bottomed pot, melt the butter with the olive oil over medium heat. Add the sliced onions and cook, stirring occasionally, until softened (about 15 minutes).
Step 2
Sprinkle the onions with sugar and salt. Continue to cook, stirring frequently, until the onions are deeply golden and caramelized (about 30–40 minutes).
Step 3
Add the minced garlic and cook for 1 minute more.
Step 4
Pour in the white wine (if using) and scrape up any browned bits from the bottom of the pot. Simmer for 2–3 minutes.
Step 5
Add the beef broth, thyme, bay leaf, and black pepper. Bring to a boil, then reduce heat and simmer uncovered for 30 minutes. Remove and discard the thyme sprigs and bay leaf.
Step 6
Preheat the broiler. Arrange the bread slices on a baking sheet and toast under the broiler until lightly golden on both sides.
Step 7
Ladle the hot soup into oven-safe bowls. Top each with a slice of toasted bread and generous handful of Gruyère cheese.
Step 8
Place the bowls under the broiler until the cheese is melted and bubbling, 2–3 minutes. Serve immediately.

Zusatztipps für die Zubereitung

To ensure success, use a large heavy-bottomed pot and a wooden spoon for stirring. Proper caramelization is key, so don't rush the onions. You will also need a cheese grater for the Gruyère and oven-safe soup bowls for the final broiling step. Using a baking sheet makes it easy to toast the bread slices evenly.

Varianten und Anpassungen

For a vegetarian version, simply substitute the beef broth with a high-quality vegetable broth. If you need a gluten-free option, use gluten-free bread slices. For a dairy-free version, use vegan butter and a dairy-free cheese alternative. If Gruyère is unavailable, Emmental or Swiss cheese are excellent substitutes.

Serviervorschläge

This soup pairs beautifully with a glass of dry white wine or a light-bodied red. For an extra boost of flavor, rub the toasted bread with a cut clove of garlic before placing it on the soup. Serve immediately while the cheese is bubbling and hot for the best experience.

A close-up of classic French Onion Soup in a crock bowl, featuring bubbly, browned Gruyère over toasted bread and savory broth. Pin It
A close-up of classic French Onion Soup in a crock bowl, featuring bubbly, browned Gruyère over toasted bread and savory broth. | hazelflour.com

Each serving of this hearty soup provides approximately 435 calories, 21g of fat, 41g of carbohydrates, and 20g of protein. It is a satisfying and complete meal that brings warmth and elegance to your table. Enjoy this French classic with friends and family for a truly comforting dinner.

Product image
Prep meals effortlessly by chopping vegetables, slicing meats, and serving dinner with the right knife always ready.
Check price on Amazon

Recipe FAQs

How long does it take to caramelize the onions properly?

Plan for about 45–55 minutes total. First soften the onions for 15 minutes, then continue cooking with sugar and salt until deeply golden and caramelized, about 30–40 more minutes. This slow process develops the sweet, rich flavor that makes the soup exceptional.

Can I make this vegetarian?

Absolutely. Substitute vegetable broth for the beef broth. The flavor will be slightly different but still delicious thanks to the deeply caramelized onions, white wine, and herbs. Many traditional bistros offer vegetarian versions using quality vegetable stock.

What cheese works best if I can't find Gruyère?

Emmental or Swiss cheese make excellent alternatives with similar melting properties and nutty flavor profiles. Comté or a mix of Parmesan and mozzarella can also work. The key is using a cheese that melts smoothly and has enough flavor to stand up to the rich onion broth.

Can I make this ahead of time?

The soup base actually improves after a day or two in the refrigerator, allowing flavors to meld. Store the soup separately from the bread and cheese. When ready to serve, reheat the soup, toast fresh bread, and broil the cheese topping just before eating.

What type of onions should I use?

Yellow onions are traditional and ideal for their balanced sweet-savory flavor. You can also use a mix of yellow and red onions for slightly different flavor notes. Sweet onions work but may caramelize faster. Avoid white onions, which can be too sharp.

Do I need oven-safe bowls?

Yes, for the traditional broiler finish. If you don't have oven-safe bowls, toast the bread and melt the cheese on a baking sheet, then float the cheesy croutons on top of the hot soup. The result is slightly different but still delicious.

Classic French Onion Soup

Deeply caramelized onions in rich beef broth, topped with crusty bread and melted Gruyère cheese for classic bistro comfort.

Prep Time
20 minutes
Time to Cook
75 minutes
Total Duration
95 minutes
Recipe Creator Gabriel Lawson


Skill Level Medium

Cuisine Type French

Makes 4 Portions

Diet Preferences None specified

Ingredient List

Onions

01 6 large yellow onions, thinly sliced
02 2 tablespoons unsalted butter
03 1 tablespoon olive oil

Broth

01 6 cups beef broth
02 1/2 cup dry white wine, optional

Flavorings

01 2 cloves garlic, minced
02 1 teaspoon sugar
03 1 teaspoon salt
04 1/2 teaspoon freshly ground black pepper
05 2 sprigs fresh thyme
06 1 bay leaf

Topping

01 4 slices crusty French bread, about 1 inch thick
02 2 cups grated Gruyère cheese

How-To Steps

Step 01

Sauté Onions: In a large heavy-bottomed pot, melt butter with olive oil over medium heat. Add sliced onions and cook, stirring occasionally, until softened, about 15 minutes.

Step 02

Caramelize Onions: Sprinkle onions with sugar and salt. Continue cooking, stirring frequently, until deeply golden and caramelized, 30 to 40 minutes.

Step 03

Add Garlic: Add minced garlic and cook for 1 minute more until fragrant.

Step 04

Deglaze Pan: Pour in white wine if using and scrape up browned bits from bottom of pot. Simmer for 2 to 3 minutes.

Step 05

Simmer Broth: Add beef broth, thyme, bay leaf, and black pepper. Bring to boil, then reduce heat and simmer uncovered for 30 minutes. Remove and discard thyme sprigs and bay leaf.

Step 06

Toast Bread: Preheat broiler. Arrange bread slices on baking sheet and toast under broiler until lightly golden on both sides.

Step 07

Assemble Bowls: Ladle hot soup into oven-safe bowls. Top each with toasted bread slice and generous handful of Gruyère cheese.

Step 08

Broil Cheese: Place bowls under broiler until cheese is melted and bubbling, 2 to 3 minutes. Serve immediately.

Tools Needed

  • Large heavy-bottomed pot
  • Wooden spoon
  • Knife and cutting board
  • Cheese grater
  • Oven-safe soup bowls
  • Baking sheet

Allergen Details

Always review ingredients for allergens. If unsure, ask a healthcare professional.
  • Contains milk from butter and cheese
  • Contains gluten from bread
  • Use gluten-free bread for gluten-free preparation
  • Use vegan butter and cheese alternatives for dairy-free preparation

Nutrition Details (one portion)

Nutrition listed here is for guidance only. It's not a substitute for medical advice.
  • Calorie Count: 435
  • Total Fat: 21 g
  • Total Carbs: 41 g
  • Protein: 20 g