This traditional French Onion Soup recipe comes directly from Paris! It's a recreation of the classic served at Au Père Louis, a beloved Parisian bistro in Le Quartier Latin, or Latin Quarter, known to have some of the best soupe à l'oignon gratinée in Paris.
(This recipe was originally published in June 2019, but was updated with new photos and content in 2020).
I have been making classic soupe à l'oignon gratinée for over 2 decades, evolving my process through years of testing and tasting. During a trip to Paris, I sampled what some consider the best French onion soup in Paris at Au Père Louis!
I spoke with who I'm guessing is the owner, and he explained the basic steps to their recipe. He provided no measurements or specifics, but I took copious notes on the method of prep, and decided to attempt this Parisian-inspired recipe upon my return to the States.
The final result is nearly identical to the soup I remember, making this the best outside of Paris too. It's très magnifique! Bon appetit!
Ingredient notes
There are many variables in a seemingly simple onion soup, but it is not a complicated recipe. Most ingredients are readily available and easily accessible. Although there are countless variations for a traditional French onion soup recipe, I find that these are the ideal ingredients for the best results.
- Oil: While some recipes call for butter, the chefs at Au Père Louis (and now I) use plain, neutral-flavored oil, like a vegetable or sunflower oil.
- Onions: You don’t need fancy (sweet) onions. Plain brown or yellow onions will do just fine. That’s actually what Julia Child used too! And don’t skimp. You’ll need a lot of onions (2 ½ pounds) to make this soup properly. Slice them into ¼-inch thick half moons.
- Garlic: Thinly slice your garlic cloves Goodfellas style.
- Flour: This acts as a slight thickener, although it's sometimes omitted in other onion soup recipes. I have always felt that adding flour gives the soup a bit more body, so I include it, as they do at Au Père Louis.
- Wine: There are different camps on what type of wine to use. This recipe uses a small amount of port or Madeira wine to add a little sweetness.
- Broth or Stock: Use good quality homemade or store-bought beef broth or stock. If you don’t have time to make homemade broth, try this beef broth concentrate. I highly recommend it for supreme convenience. You can also make this soup with a combination of beef and chicken broth (or all chicken) for a slightly less umami soup, though it’s not as traditional as all beef.
- Croutons: Cubed baguette is really essential here to get the perfect croutons for your soup. I have tried making croutons for this soup with other crusty breads, but the ratio of crust to soft bready interior is best with a baguette because it has so much more crust. Every single crouton should have a bit of crust on it for optimal texture. I may sound nitpicky but TRUST me I've been making it for decades and this is the best way to do it.
- Cheese: The best and most traditional cheese to melt on top of your soupe à l'oignon gratinée is gruyère cheese. It’s a great melting cheese from Switzerland with a slightly nutty taste.
How to make it
Begin by heating neutral-flavored oil in a large pot over medium-high heat. Add the onions and salt and toss to coat evenly with the oil (PHOTO 1). Lower the heat to medium-low, cover and cook, stirring occasionally, sweating the onions until they are softened, about 15 minutes (PHOTO 2).
Remove the lid and continue to cook uncovered, stirring occasionally another 15 to 20 minutes until most of the residual moisture has evaporated, but don’t cook long enough to caramelize (PHOTO 3).
Add the garlic and bay leaves and cook for another 3 minutes until fragrant. Stir in the flour and then the port wine (PHOTO 4).
Add hot beef broth and stir to combine. Season with more salt and pepper. Partially cover with a lid and simmer on low for about 45 minutes, stirring occasionally.
Meanwhile, preheat the oven or toaster oven to 375°F. Toss baguette cubes with the olive oil or spray them with olive oil spray, and toast in the oven for about 15 to 20 minutes until golden and crusty. Set aside.
Turn on the broiler in your oven or toaster oven. Divide the soup into 4 oven-proof bowls, top with croutons (about 1 cup per serving), and then finish with 2 to 3 ounces of grated Gruyère cheese per serving.
Make sure to evenly cover all the croutons with cheese or else the croutons could burn a little when you broil. Broil until the cheese is melted, bubbly, and golden.
Please scroll to the bottom of the post for the full recipe (in a printable recipe card) including ingredient amounts and detailed instructions.
How to make homemade beef stock (optional!)
Making beef stock from scratch is easier than you'd think, but it’s time consuming. That's the reason most people look for shortcuts. If you choose to make your own stock, I applaud you. If you don't, no judgement.
I have often made this soup with canned broth or beef broth concentrate. It's honestly delicious no matter what! This is just a touch more homemade than the alternative.
First you'll want to roast beef bones with roughly chopped onion. celery, and carrots (PHOTOS 1-2).
Carefully transfer the roasted bones and vegetables to a large stockpot. Deglaze the sheet pan with some white wine (as recommended by the staff at Au Père Louis) and water, and then pour that into the pot.
Top with more water, and then heat until simmering. You do not want to boil your stock, just cook gently. Beef stock will simmer for hours. Skim the impurities off the surface periodically (PHOTO 3).
When the stock has reduced to your liking, carefully strain it and set it aside until you're ready to use it.
One of the magical things about homemade beef stock is that it's quite gelatinous (PHOTO 4)! When you cool your stock, it will look just like Jell-O. This is from the natural collagen in the bones. When you heat the stock again, it will dissolve back into a liquid.
Expert tips and FAQs
Following my conversation at Au Père Louis, here are the main takeaways which I have utilized in this recipe:
- Use homemade stock/broth if possible
- Reduce, reduce, reduce the stock
- Slice the onions thicker, cook them in oil, but don't caramelize
- Add sliced garlic, bay leaf, dusting of flour, port wine, then stock
- Reduce, reduce, reduce
- Season generously, especially black pepper!
- Use smaller croutons (as opposed to toasted baguette slices floating on top)
The recipe I learned in Paris actually breaks one of the cardinal rules in French onion soup making!
Essentially every recipe for traditional French onion soup stipulates caramelizing the onions, sometimes for a full hour. The gentleman at Au Père Louis told me to cook the onions in oil until they are nice and soft, but specified NOT until they are caramelized. He was pretty adamant about that.
In lieu of caramelizing the onions, we add some sweet, fortified wine. At Au Père Louis they use port wine. I use Madeira. Both varieties are significantly sweeter than a run of the mill red wine. This explains why it’s unnecessary to caramelize the onions. Doing so would yield an overly sweet soup.
Many recipes top the soup with toasted baguette slices. I have done this too over the years, but find the smaller croutons SO MUCH EASIER to enjoy in my French onion soup! To get the perfect croutons, cut each slice of baguette in half and then into thirds to yield the perfect size cubes with the perfect amount of crust.
If you can’t find baguettes where you live, use the crustiest bread you can find and only cube up the edges with crust on them. Ciabatta would be an acceptable substitution as it is also quite crusty.
Trim off both ends of each onion, then halve it lengthwise (the opposite direction of where you trimmed the ends). Peel off the skin, place each onion half flat on your cutting board, and carefully slice it into ¼-inch thick slices, yielding half moons.
If you can’t get gruyère, try comté (a French cheese with similar characteristics) or emmental (the traditional Swiss cheese full of holes). Either way, make sure you grate it yourself! Don’t use pre-shredded cheeses, as they contain anti-caking agents and will not melt as evenly.
Cooked onion soup can be refrigerated for 3 to 4 days or frozen in airtight containers for 4 to 6 months.
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Soupe à l'Oignon Gratinée (Parisian French Onion Soup)
Ingredients
- 2 tablespoons vegetable oil
- 2 ½ pounds yellow onions peeled and sliced into ¼-inch thick half-moons
- 1 teaspoon kosher salt plus more as needed
- 4 cloves garlic thinly sliced lengthwise
- 2 bay leaves
- 1 tablespoon flour
- 2 tablespoons Madeira or port wine
- 6 cups beef broth or stock heated
- Freshly ground black pepper
- 4 cups (5 ½ to 6 ounces) cubed crusty baguette (¾-to-1-inch cubes)
- 1 tablespoon olive oil or olive oil spray
- 8 to 12 ounces Gruyère cheese grated
Instructions
- Heat oil in a large pot over medium-high heat. Add the onions and salt and toss to coat evenly with the oil. Lower the heat to medium-low, cover and cook, stirring occasionally, sweating the onions until they are softened, about 15 minutes.
- Remove the lid and continue to cook uncovered, stirring occasionally another 15 to 20 minutes until most of the residual moisture has evaporated, but don’t cook long enough to caramelize. Add the garlic and bay leaves and cook for another 3 minutes until fragrant.
- Stir in the flour and then the port wine. Add the hot beef broth and stir to combine. Season with more salt and pepper. Partially cover with a lid and simmer on low for about 45 minutes, stirring occasionally, skimming impurities, and adjusting seasoning as needed (don’t be stingy on the pepper!).
- Meanwhile, preheat the oven or toaster oven to 375°F. Toss the bread cubes with the olive oil or spray them with olive oil spray, and toast in the oven for about 15 to 20 minutes until golden and crusty. Set aside.
- Turn on the broiler. Divide the soup into 4 oven-proof bowls, top with the croutons (about 1 cup per serving), and then finish with 2 to 3 ounces of grated Gruyère per serving. Make sure to evenly cover all the croutons with cheese or else the croutons could burn a little when you broil. Broil until cheese is melted, bubbly, and golden.
Notes
- Cooked French onion soup can be refrigerated for 3 to 4 days or frozen in airtight containers for 4 to 6 months. I also like to freeze portions of baguette in freezer bags (because you don't use an entire baguette for this recipe so there is always extra) and then thaw them to make croutons when I am ready to enjoy another batch of this soup!
- Cubed baguette is really essential here to get the perfect croutons for your soup. I have tried making croutons for this soup with other crusty breads, but the ratio of crust to soft bready interior is best with a baguette because it has so much more crust. Every single crouton should have a bit of crust on it for optimal texture. I may sound nitpicky but TRUST me I've been making French onion soup for decades and this is the best way to do it. I usually cut each slice of baguette in half and then into thirds and they are the perfect size cubes with the perfect amount of crust.
- I have made this soup with homemade stock (recipe follows) and with beef broth concentrate. I obviously love the soup made with my homemade stock, however the soup is still excellent and flavorful with the beef broth concentrate. In a pinch store-bought broth is fine, but for a truly authentic experience aim to make your own stock if you have the time to. I’ve also tried it with equal parts beef broth and chicken broth, and it's still hearty and delicious.
- You can omit the flour entirely if you prefer a thinner broth, or increase to 2 tablespoons if you’d like a thicker broth, but I think the 1 tablespoon is optimal.
- For the port or Madeira wine, I have made this recipe with both 2 and 4 tablespoons, and prefer the lesser amount, but both are delicious so feel free to add more if you prefer a sweeter onion soup!
- Inspired by my visit to Au Père Louis in Paris
Nutrition
*All nutritional information is based on third-party calculations and should be considered estimates. Actual nutritional content will vary with brands used, measuring methods, portion sizes and more.*
Homemade Beef Stock
Ingredients
- 5 ½ to 6 pounds beef bones
- 1 large onion peeled and cut into 6 large chunks
- 2 large carrots peeled and roughly chopped
- 3 celery stalks washed and roughly chopped
- ½ cup white wine
- 4 quarts (16 cups) water
- 4 cloves garlic lightly crush with the side of a knife
- 2 bay leaves
- 2 parsley stems
- 1 tablespoon kosher salt
- 1 teaspoon peppercorns
Instructions
- Preheat the oven to 450°F. Add the beef bones, onion, carrots, and celery to a sheet pan. Roast in the oven for 1 hour, stirring once or twice during that time to ensure even roasting.
- Remove from the oven, and carefully transfer the roasted bones and vegetables to a large stockpot. Drain the fat from the sheet pan (an old jar or disposable plastic container is good for this, and hang onto it for skimming fat throughout the process).
- Deglaze the sheet pan with the white wine and 1 cup of water, scraping up any dried bits with a spatula. Pour the deglazed mixture into the pot with the bones. Add the remaining 15 cups water, and the rest of the ingredients. Heat over high heat until it just starts to bubble, but don’t boil. Immediately lower the heat to low, cover and simmer for about 2 hours. Do not stir the stock, just occasionally skim off any impurities or fat off the surface (use the jar you’ve set aside).
- Reduce the stock uncovered for at least another hour or longer (I reduced it for 3 additional hours, so a total of 5 hours). Continue to skim off the impurities and fat.
- When you’ve reduced it long enough to your liking, take it off the heat and carefully remove the bones and vegetables using a spider skimmer or small strainer. Line a sieve with a double layer of cheesecloth and set it over another pot or large bowl. Ladle the stock into the cheesecloth-lined sieve.
- Stock can be stored in jars or plastic containers in the refrigerator or freezer (leave room for it to expand once frozen). Once the stock has cooled in the fridge you can scrape off additional fat on the surface, which will solidify. Now you discard your jar of skimmed fat. Definitely NEVER dump fat down the drain, as it will harden and clog your pipes.
Nutrition
*All nutritional information is based on third-party calculations and should be considered estimates. Actual nutritional content will vary with brands used, measuring methods, portion sizes and more.*
Sheryl says
First time trying true French Onion Soup at home. Having it in France made me realize how much better it is when made without a ton of salt and prepared properly. This recipe is definitely a winner! I did use the concentrated beef stock and it turned out just wonderfully. I used the 2 Tablespoons port wine, a full baguette (8 ounces) cubed, and 12 ounces of cheese. It was so wonderful. Hubby said not to change a thing!
Kalee Gauger says
This is absolutely the best French onion soup ever! It is a definite family favorite and now that I have found this recipe it will be my go to from now on.
Reagan says
Very good!! I used this recipe to go by… but I didn’t use the measurements just so. I make French Onion Chicken and really wanted a soup version of that, and I made it! I skipped the bay leaves and added Thyme instead. YUM!
Susan says
This is just like the French Onion soup my husband and I had in Paris. Highly recommend trying this!!!!!
Cherye says
I followed the recipe exactly except that I doubled it. It was absolutely delicious! Definitely a hit! Making it again soon!
Victoria says
Doubling the recipe is BRILLIANT 🙂 I'm so glad you enjoyed the recipe!
Karen Ebner says
We actually ate here on February 15th. We could see the restaurant from our hotel balcony so we decided to try it. I googled Parisian onion soup and your blog popped up. What a coincidence! Thanks for sharing the secret. Paris was wonderful! The soup was amazing and I am making it as I type!
Victoria says
That's so awesome!! Our hotel was within walking distance, and that was actually our very first meal after we landed in Paris. What a great way to start the trip 😀 Please let me know what you think of the recipe and if it compares to your memory. I have made the soup several times and tried to pull from my memory to get it close to my personal experience. I hope it compares to yours as well!
Camille says
So this is the best French Onion Soup ever. Way better than that first batch we made 22 years ago!! HAHA. Seriously - French onion soup where you don't need to caramelize the onions? Sign me up!! I'm forever grateful that you went to Paris and got this recipe! :o)
Victoria says
It was my pleasure going to Paris and learning the secrets of the World's BEST French Onion Soup! Hahahaha 😉 I usually make this recipe about once a month now. It's just SOOO good.