French Onion Soup Recipe
This post may contain affiliate links. Please read my disclosure policy.
Mouthwatering French Onion Soup recipe makes a comforting, classic bowl of soup with caramelized onions in rich soup and crusty bread with melty, delicious cheese! A rustic yet elegant favorite for entertaining! Includes stovetop and slow cooker methods!
French Onion Soup is one of my favorite soups, especially when the temperatures outside drop – even just a little bit.
There’s something so very comforting about breaking through the cheesy, French bread exterior to get to the delicious brothy soup underneath!
While many people consider this soup to be something only served at fancy restaurants, that couldn’t be farther from the truth. A comforting yet elevated soup, this recipe is so simple to make at home and is actually believed to come from humble origins. This recipe is easy to make and great to serve anytime – it is a great comfort food and is perfect for entertaining!
Table of Contents
- Why You’ll Love This Recipe
- How to Make French Onion Soup Recipe
- French Onion Soup Ingredients
- Step-by-Step Instructions
- Recipe Tip – The Best Onions for French Onion Soup
- How to Make Slow Cooker French Onion Soup
- Step-by-Step Instructions for Slow Cooker French Onion Soup
- How to Make Ahead and Freeze French Onion Soup
- Other Favorite Cozy Soup Recipes
- French Onion Soup
Why You’ll Love This Recipe
- Impressive, yet not expensive – This soup is always impressive and has the reputation of being a “fancy restaurant” soup, making it a great soup to serve when entertaining. But it’s easy to make, and the ingredients are actually not expensive relative to many other ingredients for foods you’d serve when entertaining. Your major investment in this soup is your time to get the onions caramelized, but it is oh-so worth it!
- Full of rich flavor – The caramelized onions, buttery rich broth, and cheesy, crusty bread make this a delicious favorite all your guests will love!
- Easy to make by two methods – You can make this scrumptious soup in your Dutch oven or put all the ingredients in your slow cooker and allow it time to bubble away for you to enjoy later! Either way is easy to do!
How to Make French Onion Soup Recipe
It has always been one of those soups that I would look forward to having at restaurants, but I didn’t know how to make it at home when we first married.
It wasn’t until our third Christmas together that I tried to make it. We were hosting the soup course of a Christmas progressive dinner, and my husband requested it. It turned out perfectly and continues to be a go-to recipe for me.
French Onion Soup Ingredients
French onion soup includes a few classic ingredients for its signature flavor and presentation. You’ll need:
- Sweet onions: – See “Tips – The Best Onions for French Onion Soup” to follow. (If you are not able to find sweet onions, use yellow onions as your next choice). Make sure to slice your onions for this soup thinly. The thin slices are better for caramelizing, adding a sweet, delicious flavor to this recipe.
- Butter: It helps to brown the onions and adds flavor to the soup.
- Salt: Helps the onions to release their juices and balances the flavor.
- Olive oil: The onions cook with a bit of olive oil.
- Garlic: A clove of minced garlic adds flavor.
- Beef stock or broth: French onion soup is a broth-based soup, and I prefer to use a mixture of beef and chicken stock or broth in my soup. Since this is a broth-based soup, taste the broth before you use it, especially if you’ve never used the brand before. You want to make sure it tastes good as it is a big part of the flavor of your soup.
- Chicken stock or broth: See the note above under beef stock.
- French bread: Lightly toasted and served on top of the soup. Yum!
- Cheeses: Grated Gruyere and Parmesan cheese top the soup.
Step-by-Step Instructions
Caramelize the onions.
Slice onions thinly. Add onions, salt, and butter to a Dutch oven set over low heat. Stir occasionally until the onions have cooked down and are a caramel color, about 45 minutes to an hour. Caramelizing onions is important to the recipe and takes a bit of time, but the result is amazing depth of flavor the the best french onion soup!
Cook the garlic.
Add garlic and cook until fragrant, about 1 minute.
Stir in stock and simmer.
Then, add the beef and chicken stock and stir. Cover and let simmer for 30 minutes.
Scoop into bowls.
Ladle the soup into individual, oven-proof soup bowls.
Top with bread, cheese, and bake.
Top with toasted bread and the cheeses. Then place on a lined baking sheet and under the broiler in the oven until the cheeses have melted and browned lightly, about 8 minutes.
Recipe Tip – The Best Onions for French Onion Soup
The onion is such an important ingredient in this soup. Different onions can change the overall taste of your soup, so some types of onion make a better soup than others. While it may be a personal preference, I have tested various types of onions in my recipe through the years – cooking times, amount of caramelization, and more, to find the recipe that appeals the most – and this is it!
I’ve tested three varieties for my French Onion Soup recipe:
- Sweet Onions – sweet onions, such as Vidalia, give the soup a mildly sweet flavor without a bitter aftertaste.
- Yellow Onions – yellow onions give the soup a lot of flavor with some bitterness.
- Red Onions – red onions give the soup a strong flavor without much sweetness.
I prefer and highly suggest using sweet onions as I believe it makes the best onion for French Onion Soup. If you can not find sweet onions, yellow onions are the next best one to use.
How to Make Slow Cooker French Onion Soup
I love to make my French Onion Soup in crockpot! It is a simple process that leaves you without babysitting the onions as they caramelize or waiting for the soup to simmer.
Step-by-Step Instructions for Slow Cooker French Onion Soup
Caramelize Onions in Slow Cooker: Add your thinly sliced onions to the slow cooker, along with butter and salt. Pop the lid onto your slow cooker and set it on low heat for 10 hours. This is perfect for doing overnight so that you are ready for step two of your soup in the morning!
Make the soup: Once your onions have caramelized in your slow cooker, you are ready to move to step two with your Slow Cooker French Onion Soup! Add garlic, beef stock, and chicken stock. Stir well to combine and cook on low setting for 8 hours.
Broil and serve. When ready to serve, ladle soup into oven-proof bowls and top with bread and cheeses. Place on a lined baking sheet and under the broiler in the oven until the cheeses have melted and browned lightly, about 8 minutes.
How to Make Ahead and Freeze French Onion Soup
To make ahead: Cook French Onion Soup as directed and ladle it into oven-proof bowls. Allow the soup to cool, then cover the bowls and place them into the refrigerator for up to 3 days. When ready to serve, preheat the oven, remove the soup from the refrigerator, and place it into the oven to reheat the soup for 15 minutes. Remove from the oven and top with bread and grated cheeses. Return to the oven and bake as directed.
To freeze: Make the soup without adding the bread and cheese. Allow the soup to cool. Transfer to a freezer-safe container and freeze for up to 3 months. To serve, thaw in the refrigerator overnight and then proceed with the recipe as written. If you freeze the soup in individual portions, you can thaw and reheat only what you need.
Other Favorite Cozy Soup Recipes
Here’s my French Onion Soup recipe. I hope you love it as much as we do!
French Onion Soup
Equipment
Ingredients
- 6 medium onion, thinly sliced, sweet onion such as Vidalia
- 4 tablespoons butter
- 1/2 teaspoon kosher salt
- 2 tablespoons olive oil
- 1 clove garlic, minced
- 8 cups beef stock or broth, (64-ounces)
- 1/2 cup chicken stock or broth
- 8 slices French bread, toasted
- 2 cups Gruyere cheese, grated
- 1/2 cup Parmesan cheese, grated
Instructions
French Onion Soup Recipe (Stovetop)
- Add onions, butter and salt to large Dutch oven with olive oil set on low heat until the onions are browned and caramelized, about 1 hour. Add garlic and heat thoroughly, about one minute. Pour in beef stock and chicken stock. Stir, cover and allow to simmer over low heat for 30 minutes.
- When ready to serve, ladle soup into oven proof bowls and top with bread and cheeses. Place on lined baking sheet and under the broiler in the oven until the cheeses have melted and browned lightly, about 8 minutes.
Slow Cooker French Onion Soup Recipe:
- Add onions, butter and salt to slow cooker. Cook on low setting for 10 hours.
- Add garlic, beef stock, and chicken stock. Stir well to combine and cook on low setting for 8 hours.
- When ready to serve, ladle soup into oven proof bowls and top with bread and cheeses. Place on lined baking sheet and under the broiler in the oven until the cheeses have melted and browned lightly, about 8 minutes.
Notes
How to Make Ahead and Freeze French Onion Soup
To make ahead: Cook French Onion Soup as directed and ladle it into oven-proof bowls. Allow soup to cool and cover the bowls and place them into the refrigerator for up to 3 days. When ready to serve, preheat the oven, remove the soup from the refrigerator, and place it into the oven to reheat the soups for 15 minutes. Remove from the oven and top with bread and grated cheeses. Return to the oven and bake as directed. To freeze: Make the soup without adding the bread and cheese. Allow soup to cool, then transfer to a freezer-safe container and freeze for up to 3 months. To serve, thaw in the refrigerator overnight and then proceed with the recipe as written. If you freeze the soup in individual portions, you can thaw and reheat only what you need.Video
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
Enjoy!
Robyn xo
Yes – wondering about the Olive Oil too mentioned on the directions of making the soup – how much olive oil or is it in replacement of the butter??
Hi Germaine,
Thanks for mentioning to me – I’ve corrected the ingredients list in the recipe to include the amount of olive oil. Enjoy this – it’s delicious!
Recipe looks awesome! Where did you get those cast iron bowls? Love those!
I hope you enjoy it, Nick! It’s sooo delicious – my family loves it!
They are from Staub – I love using them! I’ve had them for a little while, but hopefully you should be able to find at any of their retailers.
Thanks!
I can’t any of these people made, at least the stovetop version because nobody questioned the “olive oil” mentioned on the first line of instructions on how to make the soup.
What about that “olive oil”?
You need oil to sweat and caramelize your onions. Butter is fine but a mix of olive oil and butter helps the butter to not burn. Kind of basic cooking knowledge.
One of my favorite soups. Hubby prefers when I use half yellow onions and half sweet onions so the flavor isn’t too sharp (but I suppose a pinch of sugar would work too). I also add just a little bit of dried thyme towards the end of cooking the onions (along with the garlic).
It’s such a great soup for fall, isn’t it Leslie?! Enjoy! xo
I did not make yet but it seems to be Yumm!!!!!!!!!!!!!!!!!!
Enjoy it Miska! It’s so delicious and comforting! Thanks!
Sounds so good…one question,is there another suitable cheese I could use?..
A local Irish pub uses Guinness Stout in place of wine. Best I’ve ever had. I’ll try your recipe.
Oh man! That does sound good!
Is there anything better than French onion soup? I think not. The last time I made it I put a bag of onions in the sous vide machine for 2 1/2 days and it worked great but I much prefer your traditional method.
I do love a good bowl of French onion soup and would have loved to have tried your way, too! How cool!
This is one of my favorites too, especially in the winter! But I’ve never been brave enough to make it. Now I have a guaranteed recipe – thanks Robyn! xo
I hope you enjoy it, Kate! It plays on repeat around here fairly often! 🙂
I am making this for arrival of family after their long road trip with beef vegetable soup too. Both are so easy to make and so very delicious. Linda