French Onion Soup is a timeless classic that blends deeply caramelized onions, rich beef broth, crusty bread, and melted cheese into one comforting and satisfying dish. Originating in France, this soup is beloved for its rustic flavors and elegant presentation. Slowly cooked onions develop a sweet and savory depth that forms the heart of this dish. When paired with crusty baguette slices and a generous amount of broiled Gruyère or Swiss cheese, the result is a warm, hearty meal that’s perfect for cold days, romantic dinners, or impressive starters at holiday gatherings. This recipe delivers traditional flavor with simple steps and ingredients found in most kitchens.
Ingredients
For the Soup:
- 5 large yellow onions, thinly sliced
- 2 tablespoons unsalted butter
- 1 tablespoon olive oil
- 1 teaspoon sugar
- 1/2 teaspoon salt
- 4 garlic cloves, minced
- 1/2 cup dry white wine (optional)
- 8 cups beef broth (preferably low-sodium)
- 1 tablespoon Worcestershire sauce
- 1 teaspoon fresh thyme leaves (or 1/2 tsp dried thyme)
- 1 bay leaf
- Salt and black pepper to taste
For the Bread Topping:
- 1 baguette, sliced into 3/4-inch thick rounds
- 1 1/2 cups grated Gruyère or Swiss cheese
- Optional: Parmesan cheese for extra browning
Preparation
Step 1: In a large soup pot or Dutch oven, melt butter with olive oil over medium heat. Add the sliced onions, sugar, and salt. Stir to coat the onions evenly. Cook, stirring frequently, for 30 to 40 minutes until the onions are deeply golden and caramelized. This step is essential, don’t rush it.
Step 2: Add the minced garlic and cook for 1 minute. Deglaze the pot with white wine (if using), scraping up any browned bits from the bottom of the pan. Let it simmer for 2–3 minutes to reduce slightly.
Step 3: Add beef broth, Worcestershire sauce, thyme, and bay leaf. Bring to a gentle boil, then reduce the heat and simmer uncovered for 30–40 minutes. Discard the bay leaf. Season to taste with additional salt and pepper.
Step 4: While the soup simmers, preheat the oven to 400°F (200°C). Arrange the baguette slices on a baking sheet. Toast in the oven for 8–10 minutes, flipping halfway, until crisp and golden.
Step 5: Preheat the broiler. Ladle hot soup into oven-safe bowls. Place 1–2 toasted baguette slices on top of each bowl, then cover generously with grated cheese. Transfer bowls to a baking sheet and broil for 2–4 minutes until the cheese is melted, bubbly, and golden brown. Serve immediately.
Variation
- Use chicken or vegetable broth for a lighter version.
- Add a splash of sherry or brandy for deeper flavor.
- Swap Gruyère with Swiss, mozzarella, or provolone cheese.
- Add a dash of balsamic vinegar near the end of cooking for complexity.
- Try using sourdough or rye bread instead of baguette.
- For a vegetarian version, use mushroom broth and skip Worcestershire sauce.
- Add roasted mushrooms to enhance the umami taste.
Cooking Note
Caramelizing the onions is the key to authentic flavor. Use medium to low heat and stir often to prevent burning. The process takes time but develops deep, sweet, and savory notes that define the soup. Deglazing the pan lifts the flavorful browned bits from the bottom, enriching the broth. Be sure your soup bowls are broiler-safe before placing them under direct heat. If you don’t have broiler-safe bowls, toast the bread with cheese separately and float it on top before serving.
Serving Suggestions
Serve French Onion Soup with a light green salad and a glass of white wine or a bold red. It also pairs well with grilled meats, roasted chicken, or a charcuterie board. As a starter, it sets the tone for elegant dinners, but it’s also satisfying enough to be a main course on its own. Offer extra toasted baguette on the side for dipping. A drizzle of olive oil or sprinkle of fresh thyme can enhance presentation.
Tips
- Use yellow or sweet onions for best flavor.
- For easier slicing, cut onions in half lengthwise before slicing thinly.
- Use day-old or lightly stale bread for best texture.
- Freeze the soup base (without bread or cheese) for up to 3 months.
- Toasting the bread beforehand keeps it from becoming soggy.
- Grate cheese fresh for the best melt and flavor.
Prep Time / Cooking Time / Total Time
Prep Time: 15 minutes
Cooking Time: 1 hour 15 minutes
Total Time: 1 hour 30 minutes
Nutritional Information
Calories: 420 per serving
Protein: 17g
Sodium: 980mg
FAQs
What kind of onions should I use?
- Yellow or sweet onions are traditional. Avoid red onions for this soup.
Can I make French Onion Soup vegetarian?
- Yes. Use vegetable or mushroom broth and omit Worcestershire sauce, or replace it with soy sauce or tamari.
What if I don’t have broiler-safe bowls?
- Toast the bread with cheese separately on a baking sheet and add it on top of the soup before serving.
Can I use different cheese?
- Absolutely. Swiss, mozzarella, provolone, or even cheddar can work in place of Gruyère.
Does this soup store well?
- The broth and onions store very well in the fridge for up to 4 days. Add fresh bread and cheese just before serving.
Conclusion
French Onion Soup is a warm, flavorful, and elegant dish that’s surprisingly easy to make at home. With deeply caramelized onions, rich broth, and that irresistible cheesy bread topping, every spoonful is layered with complexity and comfort. Whether you’re serving it as a dinner party appetizer or a cozy weeknight meal, it’s a dish that never fails to impress. Take your time with the onions, use good-quality broth, and don’t skimp on the cheese, it’s worth every minute.