Go Back
+ servings
a ladle taking a scoop of french onion soup from the pot
Print Recipe Add to Collection
4.66 from 40 votes

French Onion Soup

This French Onion Soup is a classic based on Julia Child's famous recipe. Buttery caramelized onions, rich and savory broth, cheesy toasted bread, this soup is flavorful and truly comforting.
Prep Time20 mins
Cook Time2 hrs 10 mins
Total Time2 hrs 30 mins
Course: Lunch, Soup
Cuisine: French
Keyword: french onion soup, soup recipes
Servings: 8
Calories: 412kcal


  • 2 tablespoon olive oil
  • 2 tablespoon butter unsalted
  • 1 ½ pounds yellow onions peeled, halved and thinly sliced
  • ½ teaspoon sugar
  • 1 teaspoon salt
  • 3 tablespoon all-purpose flour
  • 1 tablespoon butter unsalted
  • 6 cups beef broth low sodium or no sodium added
  • 1 cup red wine
  • 2 bay leaves
  • 3 sprigs thyme
  • 3 tablespoon cognac
  • 8 slices french baguette
  • 2 cups gruyere shredded
  • ½ cup Parmesan cheese grated


  • Caramelize Onions: In a large heavy pot such as a Dutch oven, add the olive oil and 2 tbsp of butter. Cook on medium until butter melts. Add the onions and give them a stir to coat them in the oil. Cover the pot with a lid and cook for 20 minutes with the heat still on medium, stirring every few minutes. After 20 minutes the onions should be transparent.
  • Remove the lid and stir in the sugar and salt. Continue cooking for another 40 minutes, stirring occasionally. The onions are done when they are a deep golden color and sweet. 
  • Make a Roux: Add the flour, and remaining 1 tbsp of butter and stir. Cook for about 2 or 3 minutes, just enough to cook the flour and remove that flour taste.
  • Deglaze: Add 1 cup of the beef broth to the pot and stir. Cook for about 1 minute while stirring to scrape the bottom of the pot. You'll see it evaporate almost immediately. 
  • Add broth, wine and herbs: Add the rest of the broth to the pot, followed by the red wine, bay leaves and thyme sprigs. 
  • Simmer: Bring to a boil, then turn down the heat and simmer for 30 minutes, uncovered.
  • Season and add cognac: Taste for seasoning and adjust with salt and pepper if needed. Stir in the cognac.
  • Add bread and cheese: Top the soup with about 1 cup of gruyere cheese. Add the slices of bread over the cheese. I prefer to toast my bread first then add it to the soup. To toast the bread, lightly sprinkle the bread slices with some olive oil, transfer them to a baking sheet and toast them under broil for about 30 seconds to a minute per side. Top the soup with toasted bread, then top with remaining gruyere and parmesan cheese. 
  • Melt cheese: Preheat your oven to 350 F degrees. Transfer the pot to the oven and bake until the cheese melts and starts to brown, about 20 to 25 minutes. Ladle into bowls and serve.



Onions - I prefer to to use yellow onions because of their bright flavor and sweetness. Shallots are also great because they provide a really good balance of sweetness, with bright and deep flavors.
Beef Broth or Stock - If you're not making your own stock, use a good quality beef broth, preferably with no salt added. This way you can control the salt in the soup yourself.
Wine - Use a red wine such as Cabernet Sauvignon, Merlot or a Malbec.
Cognac Alternative - If you don't have cognac, use a brandy, or simply skip it.
Cheese - French Onion Soup demands Gruyere cheese because it's rich, smooth and melts with ease!
Storage - Transfer French Onion Soup to an airtight container and store in the refrigerator for 3 to 4 days. Freeze it in covered airtight containers or heavy-duty freezer bags for up to 3 months.


Calories: 412kcal | Carbohydrates: 27g | Protein: 19g | Fat: 21g | Saturated Fat: 10g | Cholesterol: 51mg | Sodium: 1033mg | Potassium: 589mg | Fiber: 2g | Sugar: 4g | Vitamin A: 515IU | Vitamin C: 6.9mg | Calcium: 456mg | Iron: 1.6mg