This Bistro French Onion Soup Recipe is completely homemade and perfect for a chilly day! Caramelized onions, melty cheese, and crusty bread make this one of the best soups ever. It's easy enough for a novice and delicious for everyone in the family.
Now that the weather has cooled off, it's definitely soup season! One of my favorite soups is this Bistro French Onion Soup, probably because there is a lot of melty cheese involved.
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Why You'll Love This Recipe
You will fall in love with this bistro-style French Onion Soup recipe for its rich and savory broth, caramelized onions, and the irresistible combination of melted cheese and toasted bread topping that creates a heavenly experience. Not only will you have a warm and delicious soup to serve, but your house will also smell amazing when the onions are caramelizing!
Key Ingredients Needed for Bistro French Onion Soup
Yellow Onions: Yellow onions are commonly used in French onion soup for their sweet and rich flavor when caramelized. They add depth and complexity to the soup.
Unsalted Butter and Olive Oil: Butter is used for sautéing the onions and adds a creamy richness to the soup. Olive oil is often combined with butter to sauté the onions. It adds a subtle fruity flavor and helps prevent the butter from burning
Sugar: A small amount of sugar is added to aid in the caramelization process, helping the onions develop a deep, sweet flavor.
All-Purpose Flour: All-purpose flour is used as a thickening agent in traditional French onion soup. However, it can be skipped for a gluten-free option.
Beef Broth: Beef broth is the base of the soup and provides a rich and savory flavor. Chicken or vegetable broth can be substituted if preferred.
White Wine (optional): White wine can be added to add a subtle acidity and complexity to the soup.
Fresh Oregano (or any fresh herb you like): Fresh oregano or other herbs of your choice can be added for additional flavor and aroma.
Baguette: A baguette is typically sliced and toasted to create the iconic bread topping for French onion soup. It adds a crispy texture and absorbs the flavors of the soup.
Gruyere Cheese: Gruyere cheese is traditionally used for French onion soup. It has a nutty and slightly sweet flavor that melts beautifully and forms a golden crust on top of the soup.
How to make This Super Easy French Onion Soup
Step 1: Carmelize the Onions
For this recipe, I used a Dutch oven to cook the onions and soup. The heat of the cast iron helps with the onion caramelization.
Add the butter and oil and melt over medium-low heat. After the butter stops bubbling, add the onions and stir to coat the onions. Cover and cook for 15 minutes on low.
Remove the lid and add salt, pepper, and sugar to get the caramelization going. Continue to cook on medium-low heat for 25-30 minutes, stirring often, until the onions are nice and brown.
Step 2: Make The Soup Broth
Add the flour to the onions and stir for about 60 seconds. Add the broth, wine, and herbs to the onions, and cook partially covered on low heat for about 40-45 minutes.
While the soup is cooking, slice the bread into slices or large cubes and brown under a broiler for a few minutes to get them crispy.
Step 3: Broil the Cheese and Bread
Pour the soup into individual oven-safe serving bowls. Top with the bread slices or cubes and then a generous amount of cheese.
Place the bowls under the broiler in the oven until the cheese is melted and bubbly. Remove from oven and allow to cool for a few minutes before serving.
Recipe FAQs
My version of French onion soup has 51.3g of carbs per serving. Most of this is from the crusty baguette on top. So if you are watching your carbs, omit the bread.
This recipe is pretty simple and there are so many ways to adjust it to your liking. If you are gluten-free, leave out the flour.
I usually use basic yellow or white onions for French Onion Soup, but you can use any onion you like. Yellow and white onions create a nice sweetness and are usually the least expensive.
You can usually find either of these in bulk bags which makes it even more convenient and cost-efficient. Red onions will work as well but tend to be a little more bitter and sweet onions are delicious but tend to be a little more expensive.
Gruyere cheese is the most common cheese used for French onion soup. I highly recommend it not only for its melty quality but for the nutty and salty flavors you get from Gruyere.
However, if you do not have or like Gruyere, you can also use mozzarella or Monterey cheese since they both melt well. Most grocery stores have cheese experts in the cheese section and they could guide you as well.
Expert Tips for This Recipe
- Slow and Low Caramelization: Take your time when caramelizing the onions. Cook them slowly over low heat to allow the natural sugars to develop and create deep, rich flavors. This process can take anywhere from 30 to 45 minutes, but it's worth the patience for the best results.
- Use a Combination of Butter and Olive Oil: Using a combination of unsalted butter and olive oil helps prevent the butter from burning while adding a delicate fruity flavor to the onions.
- Season Gradually: Add salt and freshly ground black pepper in stages throughout the cooking process. This allows you to layer the flavors and adjust the seasoning to your preference.
- Let it Rest: After the soup is cooked, allow it to rest for a few minutes before serving. This allows the flavors to meld together and results in a more harmonious taste.
Bistro French Onion Soup Recipe
Ingredients
- 4 large yellow onions, sliced into crescents
- 3 tablespoons unsalted butter
- 2 tablespoons extra virgin olive oil
- 1 teaspoon kosher salt
- ½ teaspoon freshly ground black pepper
- 1 tablespoon sugar
- 3 tablespoons all-purpose flour (skip if you want a gluten-free option)
- 6 cups broth (beef, chicken, vegetable)
- ½ cup white wine (optional, you can sub more broth)
- ½ tablespoon fresh thyme (can sub fresh rosemary)
- ½ tablespoon fresh sage
- 1 crusty baguette sliced or cubed
- 2-3 cups gruyere cheese, shredded
Instructions
- In a large pot, add the butter and olive oil and melt over medium heat. After the butter stops bubbling, add the onions and stir to coat them. Cover the pot with a lid and cook for 15 minutes on med-low heat.
- Remove lid and add salt, pepper, and sugar to get the caramelization going. Continue to cook on medium-low heat for 25-30 minutes, stirring often, until the onions are nice and brown. Keep an eye on the heat level because you don't want them to stick and burn at the bottom.
- Add flour to onions and stir for 60 seconds, then add the broth, wine, and herbs and cook partially covered on low heat for 40-45 minutes. Add salt and pepper to taste if needed.
- While the soup is cooking, slice the bread into slices or large cubes and brown under the broiler for a few minutes to get them brown and crunchy. This only takes about 2-3 minutes per side.
- Pour the soup into individual serving bowls that are oven safe. Top with bread slices or cubes and then a generous amount of cheese. Place the bowls under the broiler in the oven until the cheese is melted and bubbly.
- Remove the bowls from the oven and allow the soup to cool for a few minutes before serving. Enjoy, and remember, it's VERY hot!!!
Notes
- Slow and Low Caramelization: Take your time when caramelizing the onions. Cook them slowly over low heat to allow the natural sugars to develop and create deep, rich flavors. This process can take anywhere from 30 to 45 minutes, but it's worth the patience for the best results.
- Use a Combination of Butter and Olive Oil: Using a combination of unsalted butter and olive oil helps prevent the butter from burning while adding a delicate fruity flavor to the onions.
- Season Gradually: Add salt and freshly ground black pepper in stages throughout the cooking process. This allows you to layer the flavors and adjust the seasoning to your preference.
- Let it Rest: After the soup is cooked, allow it to rest for a few minutes before serving. This allows the flavors to meld together and results in a more harmonious taste.
Nutrition
Any nutrition calculations are only estimates using online calculators. Please verify using your own data.
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Debra says
A favorite of ours to order in restaurants. This recipes sounds totally doable...I'm ready to take this on at home. Thank you!
Emily says
Once you make it at home you'll never have to go to a restaurant for french onion soup again!
Leslie says
Super easy and super delicious! Perfect recipe!
Emily says
Thank you!! It's always perfect when something is easy and tasty.
Kay says
OMG not only does this soup taste absolutely divine but the bread chunks with cheese on top just made it even better!! Thanks so much for the share Luke & I LOVED it. 10 out of 10
Emily says
Kay, it makes me so happy to hear you guys loved this soup. You can never go wrong with melted cheese and bread!
Chef Dennis says
Ooooh I love this French Onion Soup! Looks really delicious. Can't wait to have a bowl of this.
Amy says
If all the French dishes, this is my ultimate! I have never tried to make it before because I always think there is no way I could do it justice. But your recipe looks fab. Gonna try it this weekend!
Emily says
Thank you! It's so much easier than it looks and once you make it at home you will make it all the time!
Sarah James says
Yes please! Your French Onion Soup looks delicious and so yummy with the melted cheese. Thanks for the tip about using a Dutch oven to cook the soup in, it makes perfect sense.
Emily says
Thanks, I'm glad the tips were helpful. The dutch oven makes the best carmelized onions ever!
Alexandra says
So comforting and delicious! We made this for lunch, and we all went back for a second serve!
Emily says
I'm so glad everyone enjoyed this french onion soup, it's definitely a crowd-pleaser!
Andréa Janssen says
You can't have to many onion soup recipes, because it's so delicious. I'm going to try your recipe this fall for sure.
Emily says
You really can't have enough, I agree. I hope you like this one too!
Meesha says
I just made this for dinner and its super yum !
Emily says
Awesome, I'm so glad you liked it!
Sue says
I had been looking for an easy French Onion soup recipe, and I finally found the perfect one! This was so delicious! Thank you!
Emily says
You are so welcome, I'm glad you enjoyed it!
Taleen | Just As Tasty says
Emily!! I am so pinning this. I'm a huge fan of French onion soup but for some reason have never attempted to make it myself. This looks incredible!
Emily says
You are going to love it and it really is easy to make. The only hard part is waiting for it to cool off to eat, LOL!
Estelle Forrest says
Love love love gruyere cheese - going to have to add this to this weeks menu plan
Emily says
Oh good, the gruyere cheese alone makes this soup worth making!