Classic French Onion Soup

Featured in: Homemade Comforts

This beloved French bistro classic features a trio of slowly caramelized alliums—onions, leeks, and shallots—simmered until deep golden and sweet. The rich, beef-based broth develops incredible depth through patient cooking, enhanced with Worcestershire sauce, soy sauce, and white wine for umami complexity. Fresh thyme adds aromatic brightness while the soup gently simmers to develop its signature concentrated flavor.

The finishing touch transforms this comforting bowl into something extraordinary: toasted baguette rounds crowned with generous amounts of melted Gruyère and Parmesan. The cheese creates that irresistible, bubbly golden crust while the bread soaks up the savory broth beneath. Each spoonful delivers the perfect balance of sweet, salty, and rich flavors that have made this dish a timeless favorite.

Updated on Wed, 28 Jan 2026 01:59:27 GMT
Golden French Onion Soup is served bubbling hot in a ceramic bowl with toasted baguette and melted Gruyère. Save
Golden French Onion Soup is served bubbling hot in a ceramic bowl with toasted baguette and melted Gruyère. | oventhyme.com

Experience the ultimate comfort of a classic French bistro with this deeply savory French Onion Soup. This recipe elevates the traditional dish by incorporating a blend of caramelized yellow onions, leeks, and shallots, resulting in a complex and rich flavor profile. Simmered in a hearty beef broth and topped with bubbly, melted Gruyère over toasted baguette rounds, it is the perfect warming dish for any occasion.

Golden French Onion Soup is served bubbling hot in a ceramic bowl with toasted baguette and melted Gruyère. Save
Golden French Onion Soup is served bubbling hot in a ceramic bowl with toasted baguette and melted Gruyère. | oventhyme.com

Achieving the perfect French Onion Soup requires patience, particularly when caramelizing the alliums. This slow-cooking process transforms the sharp bite of raw onions into a mellow, sweet base that defines this timeless soup. Once deglazed and simmered, the result is a broth that is both elegant and incredibly hearty.

Ingredients

  • 4 large yellow onions, thinly sliced
  • 2 large leeks, white and light green parts only, cleaned and thinly sliced
  • 3 shallots, thinly sliced
  • 3 garlic cloves, minced
  • 3 tablespoons unsalted butter
  • 2 tablespoons olive oil
  • 8 cups high-quality beef broth (or vegetable broth for vegetarian option)
  • 1 tablespoon Worcestershire sauce
  • 2 teaspoons soy sauce
  • 1/2 cup dry white wine
  • 2 teaspoons fresh thyme leaves (or 1 teaspoon dried)
  • 1 bay leaf
  • 1 baguette, sliced into 1/2-inch rounds
  • 2 cups Gruyère cheese, grated
  • 1/2 cup Parmesan cheese, grated (optional)
  • Salt and freshly ground black pepper, to taste
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Instructions

1. Sauté Alliums
In a large heavy-bottomed pot or Dutch oven, heat the butter and olive oil over medium heat. Add the sliced onions, leeks, and shallots. Sauté, stirring frequently, until very soft and deep golden brown, about 35–40 minutes. Add the minced garlic and cook for 2 minutes more.
2. Deglaze and Simmer
Deglaze the pot with white wine, scraping up any browned bits from the bottom. Stir in the beef broth, Worcestershire sauce, soy sauce, thyme, and bay leaf. Bring to a simmer. Reduce heat and cook uncovered for 30 minutes, stirring occasionally.
3. Season
Season with salt and pepper to taste. Remove the bay leaf.
4. Toast Bread
Preheat the oven broiler. Arrange baguette slices on a baking sheet and toast under the broiler until golden, about 1–2 minutes per side.
5. Assemble and Broil
Ladle the hot soup into oven-safe bowls. Top each with toasted baguette slices and a generous amount of Gruyère (and Parmesan, if using). Place bowls under the broiler until the cheese is melted and bubbly, about 3–5 minutes.
6. Serve
Serve immediately, garnished with extra thyme if desired.

Zusatztipps für die Zubereitung

For extra umami, add a splash of sherry or cognac with the wine. Ensure you use oven-safe soup bowls to avoid any cracking while broiling the cheese.

Varianten und Anpassungen

For a vegetarian version, use rich vegetable broth and omit Worcestershire sauce or choose a vegetarian alternative. If Gruyère is unavailable, Swiss or Emmental cheese makes an excellent substitute.

Serviervorschläge

Serve this comforting soup immediately after broiling to enjoy the cheese at its stretchiest. It pairs beautifully with a crisp green salad and a glass of dry white wine.

This classic French bistro soup features deeply caramelized onions, leeks, and shallots swimming in a rich beef broth. Save
This classic French bistro soup features deeply caramelized onions, leeks, and shallots swimming in a rich beef broth. | oventhyme.com

This French Onion Soup is a testament to how simple ingredients, when treated with care and time, can create a truly spectacular meal. Whether it's a cold winter night or a weekend dinner party, this classic soup always delivers warmth and satisfaction.

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Kitchen Guide

Why does caramelizing onions take so long?

Caramelizing onions requires 35–40 minutes to break down their natural sugars and develop that deep golden color and sweet flavor. Rushing this step means missing the rich, complex taste that defines French onion soup. Patience yields the best results.

Can I make this vegetarian?

Absolutely. Simply substitute vegetable broth for beef broth and either omit Worcestershire sauce or use a vegetarian-certified brand. The result remains deliciously satisfying with the same caramelized onion depth.

What cheese works best?

Gruyère is the traditional choice for its excellent melting properties and nutty, slightly sweet flavor. Swiss or Emmental make great alternatives. Adding Parmesan provides extra savory depth and a beautiful golden crust under the broiler.

Can I prepare this in advance?

The soup 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 gently and add fresh toasted baguette with cheese before broiling.

What type of onion works best?

Yellow onions are ideal for their balanced sweetness and robust flavor. The combination of yellow onions with leeks and shallots creates layers of aromatic complexity that make this soup exceptional.

Do I need oven-safe bowls?

Yes, oven-safe bowls are essential for the final broiling step that melts and browns the cheese. If you don't have them, toast the bread with cheese on a baking sheet, then float the cheesy croutons on top of each bowl of hot soup.

Classic French Onion Soup

Savory French soup with caramelized onions, rich broth, and melted Gruyère on toasted baguette.

Prep duration
25 min
Kitchen time
80 min
Complete duration
105 min
Created by Grace Mitchell


Skill level Medium

Heritage French

Output 6 Portions

Dietary requirements None specified

What you'll need

Alliums

01 4 large yellow onions, thinly sliced
02 2 large leeks, white and light green parts only, cleaned and thinly sliced
03 3 shallots, thinly sliced
04 3 garlic cloves, minced

Fats

01 3 tablespoons unsalted butter
02 2 tablespoons olive oil

Broth & Umami

01 8 cups high-quality beef broth
02 1 tablespoon Worcestershire sauce
03 2 teaspoons soy sauce
04 1/2 cup dry white wine
05 2 teaspoons fresh thyme leaves
06 1 bay leaf

Bread & Cheese

01 1 baguette, sliced into 1/2-inch rounds
02 2 cups Gruyère cheese, grated
03 1/2 cup Parmesan cheese, grated

Seasonings

01 Salt and freshly ground black pepper to taste

Method

Phase 01

Heat fats: In a large heavy-bottomed pot or Dutch oven, heat the butter and olive oil over medium heat.

Phase 02

Caramelize aromatics: Add the sliced onions, leeks, and shallots. Sauté, stirring frequently, until very soft and deep golden brown, approximately 35 to 40 minutes. Add the minced garlic and cook for 2 minutes longer.

Phase 03

Deglaze pot: Deglaze the pot with white wine, scraping up any browned bits from the bottom.

Phase 04

Build broth: Stir in the beef broth, Worcestershire sauce, soy sauce, thyme, and bay leaf. Bring to a simmer, reduce heat, and cook uncovered for 30 minutes, stirring occasionally.

Phase 05

Season and strain: Season with salt and pepper to taste. Remove the bay leaf.

Phase 06

Prepare broiler: Preheat the oven broiler to high setting.

Phase 07

Toast baguette: Arrange baguette slices on a baking sheet and toast under the broiler until golden, approximately 1 to 2 minutes per side.

Phase 08

Assemble bowls: Ladle the hot soup into oven-safe bowls. Top each with toasted baguette slices and a generous amount of Gruyère cheese.

Phase 09

Melt cheese topping: Place bowls under the broiler until the cheese is melted and bubbly, approximately 3 to 5 minutes.

Phase 10

Serve: Serve immediately, garnished with extra thyme if desired.

Kitchen tools needed

  • Large heavy-bottomed pot or Dutch oven
  • Wooden spoon
  • Oven-safe soup bowls
  • Baking sheet
  • Chef's knife
  • Cutting board
  • Box grater or microplane

Allergy notes

Always review ingredients for potential allergens and seek professional medical advice when uncertain.
  • Contains dairy: butter and cheese
  • Contains gluten: baguette and soy sauce
  • Contains soy: soy sauce

Nutrition breakdown (per portion)

Values shown are estimates only - consult healthcare providers for specific advice.
  • Energy: 430
  • Fats: 18 g
  • Carbohydrates: 48 g
  • Proteins: 18 g