Name: French Onion Soup
Prep time: 15 min
Cook time: 25 min
Total time: 1 h
Cuisine: French
Ingredients: 4 large yellow onions, thinly sliced; 2 tablespoons butter; 1 tablespoon olive oil; 4 cups beef broth (or vegetable broth for a vegetarian version); 1 cup dry white wine (optional); 1 tablespoon fresh thyme leaves (or 1 teaspoon dried thyme); 2 bay leaves; Salt and pepper to taste; 1 tablespoon sugar (optional, for caramelization); 1 baguette, sliced into 1-inch thick pieces; 2 cups grated Gruyère cheese (or Swiss cheese)

Why You’ll Love This Recipe

French Onion Soup is a true comfort food. The combination of slow-cooked onions and rich broth creates a deeply flavorful base that’s both satisfying and delicious. The addition of melted cheese and crispy baguette croutons on top adds texture and extra flavor, making each bite even more irresistible. This soup is perfect for a chilly evening, as it’s both warming and indulgent. With minimal ingredients and some patience to allow the onions to caramelize, the results are a deeply rewarding dish.

Ingredients

(Tip: You’ll find the full list of ingredients and measurements in the recipe card below.)

4 large yellow onions, thinly sliced
2 tablespoons butter
1 tablespoon olive oil
4 cups beef broth (or vegetable broth for a vegetarian version)
1 cup dry white wine (optional)
1 tablespoon fresh thyme leaves (or 1 teaspoon dried thyme)
2 bay leaves
Salt and pepper to taste
1 tablespoon sugar (optional, for caramelization)
1 baguette, sliced into 1-inch thick pieces
2 cups grated Gruyère cheese (or Swiss cheese)

Directions

Caramelize the onions: In a large pot or Dutch oven, melt the butter and olive oil over medium heat. Add the sliced onions, and season with a pinch of salt. Cook the onions, stirring occasionally, for about 25-30 minutes until they’re golden brown and caramelized. If desired, sprinkle in the sugar halfway through to help with caramelization.
Deglaze with wine: Once the onions are caramelized, pour in the white wine (if using) and stir, scraping up any brown bits from the bottom of the pot. Allow the wine to reduce by half, about 5 minutes.
Add broth and herbs: Add the beef broth, thyme, and bay leaves. Bring the soup to a simmer and cook for 20-30 minutes, allowing the flavors to meld together. Season with salt and pepper to taste.
Prepare the croutons: While the soup simmers, preheat your oven to 400°F (200°C). Place the baguette slices on a baking sheet and toast in the oven for 5-7 minutes, or until they’re golden brown and crispy.
Assemble the soup: Remove the bay leaves from the soup. Ladle the soup into oven-safe bowls, and place one or two toasted baguette slices on top of each bowl. Sprinkle generously with grated Gruyère cheese.
Broil the cheese: Place the bowls under the broiler for 2-3 minutes, or until the cheese is melted, bubbly, and golden brown.
Serve: Carefully remove the bowls from the oven and serve immediately.

Servings and Timing

Servings: 4 servings
Prep Time: 15 minutes
Cook Time: 45 minutes
Total Time: 1 hour

Variations

Vegetarian version: Use vegetable broth instead of beef broth for a vegetarian option. You can also replace the butter with olive oil for a dairy-free version.
Cheese options: While Gruyère is traditional, you can also use Swiss cheese, fontina, or even mozzarella for a different take on this soup.
Herb variations: Add a bay leaf, fresh rosemary, or sage for additional depth of flavor.
Extra toppings: For added richness, you can sprinkle the top of the cheese with fresh parsley or a drizzle of truffle oil for an elevated flavor profile.

Storage/Reheating

Storage: Store leftover soup in an airtight container in the refrigerator for up to 3 days. The soup can also be stored without the cheese and croutons to help preserve the texture.
Reheating: Reheat the soup on the stove over medium heat. For the best experience, toast fresh baguette slices and melt new cheese on top under the broiler before serving.

FAQs

Can I make French Onion Soup ahead of time?

Yes, you can prepare the soup up to 2 days ahead. Store the soup in the refrigerator and reheat before serving. Toast the bread and melt the cheese right before serving for the best texture.

Can I use a different type of cheese?

Yes, Gruyère is traditional, but you can substitute Swiss cheese, fontina, or even provolone. For a more tangy flavor, try using a bit of Parmesan mixed with your cheese of choice.

Can I make this soup vegetarian?

Yes, just swap the beef broth for vegetable broth, and ensure you’re using a non-dairy butter alternative if needed.

Can I freeze French Onion Soup?

You can freeze the soup without the bread and cheese. Store the soup in an airtight container for up to 3 months. When you’re ready to serve, reheat the soup and top with freshly toasted bread and melted cheese.

Can I use pre-sliced onions to save time?

While pre-sliced onions can save you time, caramelizing fresh onions brings a depth of flavor that pre-sliced onions may not provide. Fresh onions are recommended for the best results.

How can I make the soup sweeter?

For a slightly sweeter flavor, add a teaspoon of sugar while caramelizing the onions. You can also use sweet onions, like Vidalia onions, for a naturally sweeter taste.

What kind of bread should I use for the croutons?

A baguette is traditional for French Onion Soup, but you can also use any crusty bread, such as sourdough or Italian bread. The bread should be sturdy enough to hold up to the soup.

Is French Onion Soup gluten-free?

No, French Onion Soup traditionally contains bread, so it’s not gluten-free. However, you can use gluten-free bread for the croutons to make it gluten-free.

Can I use store-bought broth?

Yes, store-bought broth works well in this recipe, especially if you choose a high-quality, low-sodium variety. Homemade broth adds more depth but is not necessary.

How do I make the soup less salty?

If your soup is too salty, you can dilute it with a little water or low-sodium broth. You can also balance the saltiness with a pinch of sugar or by adding more herbs.

Conclusion

French Onion Soup is a timeless classic that offers warmth, depth, and comfort in every bowl. The rich, savory broth combined with the sweet, caramelized onions and melted cheese-topped croutons is the ultimate indulgence. This recipe is perfect for a cozy dinner or special occasion, and it’s easy to customize to your liking. With its rich flavors and satisfying ingredients, French Onion Soup is sure to be a hit in any kitchen