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
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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Comments
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Hi. I am hesitant to use my broiler because my baking sheet came with instructions that said not to use it at any temp above 450 degrees. Could I use a kitchen torch instead?
Sure, Shannon, I think that should work. Enjoy!
What is a “broiler”?
Hi Jon, a broiler is a heating element in your oven that provides very high heat. Cooking food close to the broiler is similar to grilling, but with the heat directly above versus below your food. The great majority of ovens should have a broiler setting. Hope that clarifies!
I saved about 3-4 cups of broth from a pot roast. It had all the herbs and spice needed. After refrigeration, I strained out the chunks of veggies, meat and fat. The pot roast already had some red wine in it from deglazing the sauté pan but, you can’t go wrong adding sherry. Scaled up to about 20 servings, it needed a couple more pints of beef broth in addition. The pot roast broth was already reduced and loaded with potato starch so it didn’t need much time reducing the broth. No sugar, no flour, no Worcestershire sauce. It went over really well.
Made this for first time. It was delicious! Did not add any sugar or the sherry.
Definitely a keeper.
Delicious. Easy!! I only had port, not sherry, but it was still delicious!!
I had the same first impression that many others here did, that the soup was way too sweet; so to mitigate the sweetness I added an extra tablespoon of sherry, 2 tablespoons more of white wine and about another half teaspoon of black pepper. Initially I wasn’t going to use sherry because I detest it, but it actually mixed well with the flavor of the broth. I went ahead and assembled a bowl of the soup with the bread and cheese for the broiler, and I must say it was quite tasty (though I’m not convinced the overall recipe was worth the time it took to make). The only thing I will do differently on the next bowl is omit the sharp Italian cheese and just use gruyere and/or one of the milder cheeses some others suggest.
I love French Onion Soup and your recipe is pretty close to the classic version. I love it!
I did change a couple of things, mainly because I didn’t have them on hand. First, instead of white sugar, I added a very small amount (about a 1/2 teaspoon) of molasses for sweetness and depth of flavor. Too much would have really changed the flavor, but just this small amount helped with the browning of the onions and gave it some complexity.
Second, I didn’t have any beef stock, so I used vegetable stock instead. No biggie.
Third, I didn’t have an worchestershire sauce either, so I added a splash of Thai fish sauce and a splash of Liquid Aminos, along with a dash of black pepper to make up for it. That worked fine.
Fourth, I didn’t have any sherry, which I usually keep in the pantry, so I had to omit it. I did add a splash of wine near the end instead and that made it quite nice.
My end result was not the classic onion soup, but it was close and delicious, none the less.
I made this soup and it came out beautifully. It was delicious and it made such a lovely presentation. I am going to make it again this week. Everyone loved it.
I thought the recipe was very good. I added an extra tbsp of flour, a clove of minced garlic and another pinch of sugar. Perhaps the people who didn’t like it did not caramelize the onions completely or let the soup cook down enough once complete. Before the final simmer I felt like the soup needed something and was a little bland but after I let it cook down it turned out great.
We made this last night and I agree with some other comments that the soup lacked flavor. I added Worchester sauce and balsamic vinegar like other comments suggested and that helped some. We love your recipes, but were not fond of this soup.
I made this two days ago and here is my take: it is an excellent recipe and letting it sit in the frig overnight really enhances the flavors.
However, for me, the next time I make it will will omit the bay leaves and add beef bullion to get a beefier taste with the onions.
I will make this again no doubt, but with a couple of personal adjustments.
Thank you for this delicious recipe!