French Onion Soup
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Rich, caramelized onions simmered in a savory broth and topped with golden, melty cheese—this French onion soup is pure comfort.
French onion soup might be a staple on restaurant menus, but it started as a humble peasant dish made from just onions, stale bread, and water. Today, it’s a bit more refined but still wonderfully simple to make at home. The secret is patience: the onions need to cook low and slow until they’re deeply caramelized and sweet. I like to add a touch of flour to slightly thicken the broth and finish the soup with two kinds of cheese—techniques I picked up while working in a restaurant renowned for its incredible French onion soup recipe.
“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
- 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, Worcestershire sauce, dried thyme, and bay leaves: Form the savory, aromatic base of the soup—rich, deep, and full of umami.
- 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 and Parmigiano Reggiano: Melt into a golden, bubbling layer with creamy, nutty flavor and a hint of sharpness. For the best results, look for authentic imported cheeses—Gruyère should have “AOC” on the label, and the parm should say “Parmigiano Reggiano,” not “Parmesan,” to ensure you’re getting the real thing.
- Jump to the printable recipe for precise measurements
Step-by-Step Instructions
Step 1: Caramelize the onions. Melt the butter in a large Dutch oven or soup pot over medium heat. Add the oil, onions, salt, pepper, and sugar. Cook, stirring occasionally, until the onions are a deep golden brown and completely caramelized, about 50 minutes. Don’t rush this step—properly caramelized onions should be soft and rich in color. Your kitchen will smell amazing.
Step 2: Deglaze. Pour in the wine and cook, stirring with a wooden spoon to loosen the browned bits from the bottom of the pan—there’s tons of flavor there. Continue cooking until the liquid is almost gone and the onions are jammy.
Step 3: Thicken the base. Add the flour and stir for about a minute, just until it disappears into the onions—this helps thicken the broth and give it some body later on.
Step 4: Build the broth. Add the broth, Worcestershire sauce, thyme, and bay leaves to the pot. Bring to a boil, then reduce the heat and simmer for about 30 minutes. Once done, add the sherry.
Step 5: Toast the bread. While the soup simmers, arrange the baguette slices on a baking sheet in a single layer. Bake until crisp and golden, about 10 minutes, then set aside to cool.
Step 6: Assemble the crocks. Heat the broiler and place the soup crocks on a baking sheet for easy handling. Ladle the hot soup into the crocks, then top each with a toasted baguette slice and a generous handful of cheese.
Step 7: Broil and serve. Slide the crocks under the broiler and cook until the cheese is bubbling and golden brown, 2 to 4 minutes. Let the soups cool for a few minutes before serving—they’ll be piping hot and perfectly melty.
Video Tutorial
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Classic French Onion Soup
Ingredients
- 4 tablespoons unsalted butter
- 1 tablespoon vegetable oil
- 3 lbs 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 (13-mm) slices
- 1 tablespoon dry sherry
- 8 oz 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 (205°C) 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 in (15 cm) from the broiler element and heat the broiler. Place the oven-proof crocks on a baking sheet (see note below if you don’t have oven-proof crocks). Fill them with very hot soup, top each with 1 or 2 baguette slices without overlapping, and sprinkle evenly with Gruyère and Parmigiano Reggiano. Broil until the cheese is melted and bubbly around the edges, 3 to 5 minutes. Let the crocks cool for a few minutes before serving.
Notes
- If you don’t have oven-proof soup crocks, place the toast slices on a baking sheet, top each with cheese, and broil for about 2 minutes, until the cheese is melted. Divide the hot soup among regular bowls and top each serving with the cheese toasts.
- Make-Ahead Instructions: The soup can be made and refrigerated up to 3 days ahead (without toasts or cheese), or frozen for up to 3 months. The toasts can be made (without the cheese) and kept sealed at room temperature for up to 3 days.
Nutrition Information
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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First let me say that I love Jen’s recipes and I have been making them for years. The French Onion Soup recipe I found to be way too sweet. After looking at other recipe ingredients for French Onion Soup I have to conclude that it is the sweet onions that made it far too sweet. Every other recipe I looked at called for yellow onions.
I had a dinner party with a few courses with wine pairing and of all the dishes, this was a huge hit. Mind you, some of the guests were complete wine snobs and food snobs as well and they thought this soup was high end restaurant quality! A few things:
This took longer than it indicated. Maybe it was my cast iron pot or the electric stove, but I was super patient in the caramelisation of the onions and it paid off. I made the broth first, set it aside and added the bay leaves and fresh thyme in the broth to let sit for a few hours while I caramelised the onions. I have no idea if that made any difference at all… I also, used 1 3/4 cup wine instead of one cup and we put it on low for at least 4 hours the night BEFORE serving it. I will definitely make this again!
I’m impressed!
It took me MUCH longer to caramelise me onions but I was determined not to bail out before they reached the desired colour.
I used bog standard onions and homemade chicken stock.
(I also decided to chuck in a whole roasted garlic that I’d found in the freezer).
I doubled the Worcestershire Sauce and Sherry, left the sugar out and added slightly more salt & pepper but I’d advise tasting as you go along.
In hindsight I think the 1tbsp of sherry would’ve sufficed because once the soup had simmered for 30 minutes it seemed to increase in sweetness.
Definitely restaurant quality and knocks the socks of anything you’d buy in a tin!
Excellent recipe. Added 1tbs of fish sauce to combine with the beef broth and bring out umame flavor.
This is such an excellent recipe with rich flavor. The only thing I did differently is to cut the bread into cubes after toasting in the oven. Then put the bread cubes on a cookie sheet, top with the cheeses and broil. Then slide onto the top the bowl of soup. I also had some left over short ribs that I added at the bottom of the bowl before topping with the soup. Not that it needed it, but it was just to utilize left overs. Another awesome recipe from Jen.
I actually just came back from Paris a few weeks ago and I had no plans this past rainy Saturday morning and I thought, “You know what, I am going to make some french onion soup!” Jennifer the soup was amazing, It was my first time making it and I am SOO PLEASED! It was everything I wanted to be. It was the closest thing possible to the soup I had at one of my favorite restaurants in Paris, so thank you for gifting us with this recipe and easy instructions!
Why sugar? I am certain the classic version does not have sugar.
Hi Frank, the little bit of sugar helps to balance out the other flavors (similar to adding salt to batter when baking).
Sugar also helps develop nice color to the onions.
I can’t remember if I’ve already reviewed this recipe, so apologies if I have, but I’m making this for a fourth time and just wanted to say how delicious it is. Best recipe ever! 😃
So yummy! Now, where do we find those oh so cute crocks? 😉
Glad you liked it! You can find the crocks at Sur la Table.
You can also find the crocks at many estate sales, I’ve amassed quite a few realllllly nice ones over the years.
Ms. Segal: I cannot thank you enough for being my go-to recipe database (for salads, mains and desserts). My all-time favourite meal is YOUR chicken marsala with YOUR Caesar salad (genius to use mayo instead of eggs), and YOUR chocolate cream pie for dessert.
As for this soup, I impulsively bought an entire bag of shallots at a wholesaler yesterday. Do you suppose I could substitute shallots for onions entirely?
Hi Kathryn, thanks for your nice words about the recipes – so glad you like them! Yes, I think you could get away with using shallots for the soup; I’d love to hear how it turns out if you make it!
How many servings can I have from your French onion soup?
This serves 4 to 6.