French Onion Soup
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Rich, caramelized onions simmered in a savory broth and topped with golden, cheesy croutons—French onion soup is the ultimate comfort food.
French onion soup might be a classic restaurant dish, but it actually began as a simple peasant meal made with onions, stale bread, and water. These days, it’s a bit more refined but still easy to make at home. The secret lies in slowly caramelizing the onions until they’re sweet and golden brown. I like to add a pinch of sugar for sweetness, stir in a bit of flour for body, and top the soup with two kinds of cheese—tricks I picked up working in a high-end restaurant known for its incredible French onion soup recipe.
No ovenproof crocks? No problem—melt the cheese on toasts and serve them on the side or place them right on top. You can even prep the broth and toasts ahead, so all that’s left is broiling.
Table of Contents
“I made this last night and it was amazing! I think it was even better than the French Onion Soup we had in Paris last summer.”
What You’ll Need To Make French Onion Soup
- Unsalted butter and vegetable oil: Used to caramelize the onions (the oil prevents the butter from burning).
- Vidalia (or sweet) onions: Lend a naturally sweet, mild flavor when caramelized.
- Sugar: Helps amplify the natural sweetness of the onions and aids in caramelization.
- Dry white wine: Deglazes the pan, dissolving the fond for a deep, complex flavor.
- All-purpose flour: Thickens the broth for a slightly hearty consistency.
- Beef broth: Forms the savory base of the soup, adding depth and richness.
- Worcestershire sauce: Enhances the umami flavor in the broth.
- Dried thyme and bay leaves: Infuse the broth with warm, earthy, and woodsy aromatics.
- Baguette: Serves as the base for the cheesy croutons.
- Dry sherry: Adds a layer of complexity and a slightly sweet, nutty finish to the broth.
- Gruyère cheese: Melts beautifully, creating a creamy, nutty topping. Look for an imported Swiss variety for the best flavor.
- Parmigiano Reggiano: Adds sharpness and depth to the cheesy topping, complementing the Gruyère.
- Jump to the printable recipe for precise measurements
Step-by-Step Instructions
To begin, in a large Dutch oven or soup pot, melt the butter over medium heat. Add the oil, onions, salt, pepper, and sugar.
Cook, stirring occasionally, until the onions are deep golden brown and caramelized, 45 to 55 minutes. At this point, you’ll have beautifully caramelized onions.
Add the wine.
Cook, stirring with a wooden spoon to scrape any fond from the bottom of the pan, until almost all of the liquid has evaporated and the onions are jammy, 8 to 10 minutes.
Add the flour.
Cook for about one minute to dissolve the flour, then add the broth, Worcestershire sauce, thyme, and bay leaves to the pot.
Bring to a boil, reduce the heat to a simmer, and cook, covered, for about 30 minutes. Add the sherry, then taste and adjust seasoning if necessary.
While the soup simmers, preheat the oven to 400°F and set an oven rack in the middle position. Arrange the baguette slices in a single layer on a baking sheet. Bake until the bread is dry, crisp, and golden at edges, about 10 minutes. Set aside.
Adjust an oven rack 6 inches from broiler element and heat broiler. Set individual broiler-safe crocks on a baking sheet and divide the hot soup among the crocks. Top each crock with 1 or 2 baguette slices.
Sprinkle evenly with Gruyère and then Parmigiano Reggiano.
Slide the crocks into the oven and broil until the cheese is melted and bubbly around edges, 3 to 5 minutes.
Let the French onion soup crocks cool for a few minutes before serving.
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Video Tutorial
French Onion Soup
Rich, caramelized onions simmered in a savory broth and topped with golden, cheesy croutons—French onion soup is the ultimate comfort food.
Ingredients
- 4 tablespoons unsalted butter
- 1 tablespoon vegetable oil
- 3 pounds Vidalia (or sweet) onions (about 5 medium), halved lengthwise and thinly sliced
- ¾ teaspoon salt
- ½ teaspoon freshly ground black pepper
- ¾ teaspoon granulated sugar
- 1 cup dry white wine
- 2 tablespoons all-purpose flour
- 6 cups beef broth
- 1 teaspoon Worcestershire sauce
- ½ teaspoon dried thyme
- 2 bay leaves
- 1 small baguette, cut into ½-in slices
- 1 tablespoon dry sherry
- 8 ounces Gruyère cheese, grated (about 2 heaping cups; look for one imported from Switzerland)
- ½ cup grated Parmigiano Reggiano
Instructions
- In a large Dutch oven or soup pot, melt the butter over medium heat. Add the oil, onions, salt, pepper, and sugar. Cook, uncovered, stirring occasionally with a wooden spoon, until onions are deep golden brown and caramelized, 45 to 55 minutes. In the beginning, you will only need to stir the onions occasionally. As they start to brown midway through cooking, you will need to stir them frequently, scraping the fond (the brown particles) from the bottom of the pan. If the onions are browning too quickly, reduce the heat slightly or add a few tablespoons of water to deglaze the pan and continue cooking.
- Add the wine and raise the heat to high. Cook, stirring with a wooden spoon to scrape any fond from the bottom of the pan, until almost all of the liquid has evaporated and the onions are jammy, 8 to 10 minutes.
- Add the flour and cook, stirring constantly, for one minute.
- Add the broth, Worcestershire sauce, thyme, and bay leaves to the pot. Bring to a boil, reduce the heat to a simmer, and cook, covered, for about 30 minutes.
- While the soup simmers, preheat the oven to 400°F and set an oven rack in the middle position. Arrange the baguette slices in a single layer on a baking sheet and bake until the bread is dry, crisp, and golden at edges, about 10 minutes. Set aside.
- When the soup is finished, remove the bay leaves and add the sherry; taste and adjust seasoning if necessary. If the soup needs a deeper flavor, try a few shakes of Worcestershire sauce. If it's not quite sweet enough, add ¼ teaspoon sugar.
- Adjust an oven rack 6 inches from broiler element and heat broiler. Set individual broiler-safe crocks on a baking sheet and divide the hot soup among the crocks (be sure the soup is very hot as it won't warm up much in the oven). Top each crock with 1 or 2 baguette slices (do not overlap slices) and sprinkle evenly with Gruyère and then Parmigianno Reggiano. Slide the crocks into the oven and broil until the cheese is melted and bubbly around edges, 3 to 5 minutes. Let the crocks cool for a few minutes before serving. (Alternatively, if using regular soup bowls: Top each toast slice with some cheese and return to broiler to melt, about 2 minutes more. Divide the soup among bowls and top each serving with two cheese toasts.)
- Make-Ahead Instructions: The soup can be made and refrigerated up to 3 days ahead (without toasts or cheese), or up to 3 months ahead and frozen. Toasts can be made (without the cheese) and kept sealed at room temperature for up to 3 days.
Nutrition Information
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- Per serving (5 servings)
- Calories: 642
- Fat: 31 g
- Saturated fat: 17 g
- Carbohydrates: 53 g
- Sugar: 19 g
- Fiber: 4 g
- Protein: 31 g
- Sodium: 1,697 mg
- Cholesterol: 82 mg
This website is written and produced for informational purposes only. I am not a certified nutritionist and the nutritional data on this site has not been evaluated or approved by a nutritionist or the Food and Drug Administration. Nutritional information is offered as a courtesy and should not be construed as a guarantee. The data is calculated through an online nutritional calculator, Edamam.com. Although I do my best to provide accurate nutritional information, these figures should be considered estimates only. Varying factors such as product types or brands purchased, natural fluctuations in fresh produce, and the way ingredients are processed change the effective nutritional information in any given recipe. Furthermore, different online calculators provide different results depending on their own nutrition fact sources and algorithms. To obtain the most accurate nutritional information in a given recipe, you should calculate the nutritional information with the actual ingredients used in your recipe, using your preferred nutrition calculator.
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Excellent recipe! It was delicious.
I made this tonight and it turned out AMAZING!! I’ve never made French onion soup and really had in mind that specific taste when it’s really good and you get it at a restaurant. This recipe does just that. I followed the steps and ended up adding 8 onions- felt like I could have added more just for my personal preference, I like a lot. The flavor was so amazing. With soup you have a lot of leeway to add until you get it perfect and that’s what I did here- but the general instructions are a great guide and I couldn’t be happier with how it turned out. Will be adding to my recipe book and am seriously considering making a big batch and canning it. Will def be exploring more recipes from Jenn in the future.
Another hit! Ok, you are now my go-to site for every recipe. Thank you.
I have made this several times, including today, as a rainy day comfort food. I use toasted slices of homemade no knead crusty bread instead of a baguette. This recipe is amazing!
I plan to make this soup and don’t have white wine as we are red wine drinkers. I keep a large bottle of Martini and Rossi vermouth on hand for cooking since once opened it will keep so much longer than wine. My question is can I use vermouth in this recipe?
Many thanks.
Jan 🇨🇦
Sure, Jan, that should work. Hope you enjoy!
The best French Onion Soup I have ever made. Thanks for this excellent recipe. 😷
I don’t know why I’ve always been intimidated by the thought of making french onion soup, but I was. No longer! This recipe was not at all difficult, and it was lip-smacking good! I felt like a fancy cook when I served it. Thank you, Jenn, for helping me to be a more confident cook.
This is my first review of a recipe ever…and so a little background. I love to cook and I love French style cooking. (I lived in France one summer with my family and absolutely love the food and the lifestyle…rich foods…full but good fats…fresh in season ingredients…relaxing and enjoying good food with family and friends. We have embodied this ever since. :)) I found Once Upon a Chef and started to follow about 6 months ago. It is the only cooking blog that I choose to follow. The reason…it is the only one out there that I have seen with a classically trained chef (trained in France no less!), and every recipe that I have tried has been amazing. This French Soup recipe is no exception. It is rich and comforting. Perfect for our cold nights! The only thing that I did different is use brown onions (I just prefer them but will try it next time with the sweet onions), gluten free flour, and gluten free French bread on top. I know that real French bread would be much better, but we make do with our gluten sensitivity. Bon Appetit!
It’s official-this is now our favourite soup! So easy and oh so good. The broth is so flavourful and lower in sodium than what I’ve had in restaurants. I put in only about 2 lbs of onions, personal taste, and use Swiss cheese since it’s something I usually have in the fridge.
Thanks Jenn for another great recipe.
I have tried many French Onion Soup recipes and this one became my favorite. My family asks for it frequently.