French Onion Soup

5 from 3 votes

Deeply caramelized onions simmered in a rich, savory broth make this French Onion Soup a true classic that's both comforting and indulgent. Topped with toasted baguette slices and melted Gruyère cheese that's bubbly and golden, each spoonful offers a harmonious blend of textures and flavors.

Prep Time15

Cook Time1 15

Total Time1 30

Course: Dinner, Lunch, Soup

Cuisine: French

Servings:

Calories: 687kcal

Author: Joanna Cismaru

Equipment

6 Quart Dutch Oven

Ingredients

4 large onions thinly sliced
3 tablespoons butter
1 tablespoon olive oil
2 cloves garlic minced
1 teaspoon sugar
1 teaspoon salt
1 cup dry white wine
8 cups beef broth low sodium or no sodium added
2 bay leaves
1 teaspoon dried thyme
1 baguette sliced
2 cups Gruyère cheese grated
salt and pepper to taste

US Customary - Metric

Instructions

In a large pot or Dutch oven, melt 3 tablespoons of butter with 1 tablespoon of olive oil over medium heat.
Add the thinly sliced onions and cook for about 10 minutes until they are soft and translucent.
Sprinkle 1 teaspoon of sugar and 1 teaspoon of salt over the onions. Continue to cook, stirring frequently, for about 30-40 minutes until the onions are deeply caramelized and golden brown. Be patient, as this step is crucial for the flavor of the soup.
Add 2 cloves of minced garlic to the pot and cook for another minute. Pour in 1 cup of dry white wine to deglaze the pot, scraping up any browned bits from the bottom. Let the wine simmer until it is mostly evaporated.
Add 8 cups of beef broth, 2 bay leaves, and 1 teaspoon of dried thyme. Bring the soup to a boil, then reduce the heat and let it simmer for about 30 minutes. Season with salt and pepper to taste.
While the soup is simmering, preheat your oven to 400°F (200°C). Arrange the baguette slices on a baking sheet and toast in the oven for about 5-7 minutes, or until golden and crisp.
Remove the toasted baguette slices from the oven and sprinkle each slice with grated Gruyère cheese. Return to the oven for a few more minutes until the cheese is melted and bubbly.
Ladle the hot soup into oven-safe bowls. Place a few cheesy baguette slices on top of each bowl of soup.
Preheat your broiler. Place the bowls on a baking sheet and broil for 2-3 minutes, or until the cheese is melted and bubbly.

Notes

Caramelize Slowly: Take your time with the onions to develop that deep, rich sweetness—it's key to the soup's flavor.
Use Good Wine: Choose a wine you enjoy, whether it's a dry white or bold red, as it enhances the overall taste.
Experiment with Cheese: While Gruyère is traditional, feel free to mix in Emmental or cheddar for added flavor.
Broth Matters: Homemade beef broth adds incredible depth, but a high-quality store-bought version works in a pinch.
Fresh Herbs Boost Flavor: Adding fresh thyme or rosemary while simmering elevates the soup’s aroma.
Deglaze for Flavor: Scraping the browned bits during deglazing is essential for unlocking maximum flavor.
Leftovers Improve: The soup tastes even better the next day—just make fresh cheesy baguette slices when reheating.

Nutrition