The Most Famous French Onion Soup – Rich, Savory & Classic

Why You’ll Love This Recipe

I love this French Onion Soup because it’s simple yet incredibly flavorful. The key is in the caramelization of the onions, which brings out their natural sweetness and adds a rich depth to the soup. The broth, infused with herbs and wine, elevates the soup to another level, and the golden, melted cheese on top of a crispy baguette makes every bite irresistibly comforting. Whether it’s for a cozy evening or a special dinner, this soup is always a hit!

Ingredients

• 4 large yellow onions, thinly sliced

• 2 tbsp unsalted butter

• 1 tbsp olive oil

• 1 tbsp olive oil (second addition for sautéing)

• 4 cups beef broth (or vegetable broth for a vegetarian version)

• 1 cup dry white wine (optional but recommended)

• 2 tsp fresh thyme leaves (or 1 tsp dried thyme)

• 1 bay leaf

• Salt and freshly ground black pepper, to taste

• 1-2 French baguettes, sliced into 1-inch thick slices

• 2 cups grated Gruyère cheese (or a mix of Gruyère and Swiss cheese)

(Hint: Check out the full list of ingredients and measurements in the recipe card below.)

Directions

Caramelize the Onions:

1. Prepare the Onions: In a large, heavy-bottomed pot or Dutch oven, heat butter and olive oil over medium heat. Add the sliced onions and stir to coat in the butter and oil.

2. Cook the Onions: Cook the onions slowly, stirring occasionally, for about 40-45 minutes. The goal is to caramelize the onions, not burn them, so be patient. Stir occasionally to ensure the onions cook evenly and become deeply golden brown and sweet. The process of caramelization is key to achieving that rich, savory flavor.

Make the Soup:

3. Deglaze with Wine: Once the onions are caramelized, add the white wine (if using) to the pot to deglaze. Scrape the bottom of the pot with a wooden spoon to lift up any flavorful bits stuck to the pan. Let the wine simmer for about 2-3 minutes, reducing slightly.

4. Add the Broth and Herbs: Add the beef broth, thyme, and bay leaf to the pot. Bring to a simmer, then reduce the heat to low. Let the soup simmer gently for 30-40 minutes, allowing the flavors to meld together. Season with salt and pepper to taste.

Prepare the Baguette:

5. Toast the Baguette: While the soup is simmering, preheat your oven to 375°F (190°C). Place the sliced baguette pieces on a baking sheet and toast in the oven for 10-12 minutes, or until they are crispy and golden brown.

6. Top with Cheese: Once toasted, remove the baguette slices from the oven and set aside.

Assemble and Serve:

7. Top the Soup with Toasted Baguette and Cheese: Ladle the hot soup into oven-safe bowls. Place one or two pieces of the toasted baguette on top of each bowl of soup. Sprinkle a generous amount of grated Gruyère cheese over the baguette slices.

8. Broil: Place the bowls under the broiler for 2-3 minutes, or until the cheese is melted and bubbly, with a golden brown color. Be careful not to burn the cheese.

9. Serve: Remove the bowls from the oven and let them cool for a minute before serving. Garnish with a sprinkle of fresh thyme if desired, and serve immediately.

Servings and Timing

This recipe serves about 4 people. Prep time is around 10 minutes, with cooking time for the onions taking about 40-45 minutes. Simmering the soup takes 30-40 minutes, and the broiling time adds another 5 minutes. Overall, the dish takes about 1.5 hours to prepare, making it perfect for a cozy dinner or special occasion.

Variations

This classic French Onion Soup can be customized in a few ways:

• Vegetarian Version: Substitute vegetable broth for the beef broth, and make sure the cheese used is vegetarian-friendly (some cheeses may use animal rennet).

• Wine-Free: If you prefer not to use wine, you can simply skip it and increase the broth slightly to make up for the liquid. A splash of apple cider vinegar can add a touch of acidity in place of wine.

• Cheese Options: If you can’t find Gruyère, try Swiss cheese or Comté for similar flavors. You can also add a mix of cheeses for a more complex taste.

• Add More Herbs: Try adding a sprig of rosemary or a couple of garlic cloves while simmering the soup to infuse more flavor.

Storage/Reheating

Store any leftover soup in an airtight container in the refrigerator for up to 3-4 days. The soup will stay flavorful for a couple of days, but the baguette and cheese topping will lose their crispiness. To reheat, warm the soup on the stove and top with fresh toasted baguette and cheese, then broil for a few minutes to melt the cheese again.

FAQs

Can I make this soup ahead of time?

Yes! You can make the soup base and store it in the refrigerator for up to 2 days. When ready to serve, reheat the soup, toast the baguette slices, and broil with the cheese on top. This way, you’ll have a delicious, freshly melted cheesy topping every time.

Can I freeze this soup?

Yes, you can freeze the soup base (without the baguette and cheese) for up to 2 months. Thaw it in the refrigerator overnight and reheat it before serving. Add fresh, toasted bread and cheese just before broiling.

Can I make this soup without the broiling step?

Yes, you can skip the broiling step and simply serve the soup with the toasted bread and melted cheese placed on top. The broiling step just adds a crispy, golden layer of cheese, but it’s optional.

What if I don’t have oven-safe bowls?

If you don’t have oven-safe bowls, you can assemble the soup with the bread and cheese in a regular bowl, then transfer it to a baking sheet or dish to broil.

Can I add meat to this soup?

Yes! While classic French onion soup is typically vegetarian, you can add shredded beef or even some grilled chicken for a heartier version.

Conclusion

This French Onion Soup is rich, savory, and soul-warming, with its deep caramelized onions, flavorful broth, and melty cheese topping. It’s a classic dish that’s simple to make yet deeply satisfying, perfect for cozy nights in or special gatherings. With a crispy baguette and golden, bubbly cheese on top, this soup is everything you could want in a comforting, flavorful meal.