This easy french onion soup is warm, rich, and savory with caramelized onions, toasted baguettes, and gooey melted gruyère and comtè cheese. Indulge with a bowl of this authentic french onion soup on a chilly day and warm up from the inside out!
Onions are cooked until golden brown, sweet, and flavorful. Build the flavors with wine, garlic, and other savory sauces. Then add toasted bread and mounds of cheese just before broiling it to melty perfection. Trust me when I say, you are going to love the process of making these French onion soup bowls.
Why This French Onion Recipe Works
- Ultimate Comfort Food – Warm and cozy, this recipe is perfect for a cold day.
- Easy to Prepare – These simple step-by-step instructions make this recipe great for beginners. The ingredient list may seem extensive but I guarantee that you have most of the components already stocked in your kitchen.
- Better Than Restaurant Quality – Homemade french onion soup just hits differently and this recipe is all about good ingredients. We don’t skimp on quality or flavor.
The Origin of French Onion Soup
One origin story insists the soup was invented by King Louis XV during a hunting trip. With only butter, onions, and champagne, the first french onion soup was created and the rest is culinary history!
A more humble and likely tale references the soup as a meal for the poor, dating back to the Romans. The modern version of the recipe came about during the 18th century in France.
Tools You Will Need
6 quart Dutch oven
Ingredients You Will Need for Shirred Eggs
This section details what you will need to make this recipe, the use of each ingredient, and substitution options. For the exact measurements, see the recipe card below.
- Yellow onions – Halve them and then thinly slice.
- Butter – Is it a French recipe without butter? This is used to carmelize the onions and a bit more is added to the broth later on for taste.
- Olive oil – Add this when carmelizing the onions.
- Fresh thyme – This infuses the broth with fresh herby flavor and is scooped out just before the bread and cheese are added.
- Dry white wine – I use sauvignon blanc to deglaze the pan.
- Brandy – This enhances the other flavors.
- Fresh garlic – Minced.
- Worcestershire sauce – For umami flavor, this is essential.
- All-purpose flour – This thickens the soup, adding body.
- Homemade beef stock – This is the base of the soup so it needs to be good. Try my homemade beef stock recipe or a quality store-bought variety with low sodium.
- Fish sauce – Although this does not have a fishy taste, it does add depth to the overall flavor.
- Seasoning – I use freshly cracked black pepper and kosher salt (to taste).
French Bread Toast
- French baguette – Cut into ½-inch thick slices.
- Olive oil – This is used to brown the bread.
- Garlic clove – Halved.
- Cheese – I use freshly grated gruyère cheese and comtè cheese.
The Best Onions for French Onion Soup
Although you can use white onions, red onions, and shallots for French onion soup recipes, I prefer using yellow or a mix of yellow onions and sweet onions. Yellow onions are the classic choice as they have a delicious subtle sweet flavor when caramelized.
You can also use shallots and I’ve even seen some recipes call for using red onions. Depends on your preference, just ensure they are sliced thin.
The Best Cheese for French Onion Soup
Gruyère cheese is the classic choice. This aged swiss cheese melts beautifully to create fondue, mac and cheese, and the delicious golden brown topping for this french onion soup. It’s creamy and soft, with a hint of nutty flavor.
I also use comtè cheese because it is savory, with an interesting fruity nutty twist. This French cheese also melts really well.
Dry White Wine for French Onion Soup
Wine deglazes those browned bits (also known as fond) that may stick to the pan as the onions caramelize. And as it cooks, the flavor becomes more concentrated. I use Sauvignon Blanc but Pinot Grigio is tasty, too.
Another great option is dry vermouth. I use Lo-Fi, which doubles as a terrific ingredient to make martinis (+21). If you happen to have brandy on-hand use that, too! It’s full-bodied flavor will make a difference in your french onion soup.
A good rule of thumb is don’t use it if you wouldn’t drink a glass of it. If you don’t want to use alcohol, you can replace it with more beef stock but the flavor dry white wine provides is truly unmatched.
How To Make French Onion Soup
Take time to build the flavors of this soup then top it with crunchy toasted bread and a delicious blend of cheese.
Over medium heat, add 3 tablespoons of butter and 1 tablespoon olive oil. Once melted, add the onions and stir every few minutes. Do not rush this process because caramelizing onions takes about 45 minutes. As you cook the onions, take care to not let the mixture brown too quickly, rather it should slowly brown over time.
Add Other Ingredients & Simmer
If the mixture dries out, add 1½ teaspoons of water at a time and stir. After 35 minutes, stir in garlic and continue to cook until onions turn deep brown in color. Stir in the white wine and brandy. Cook until the liquid reduces by about half, 3-4 minutes.
Stir in flour and cook until the mixture slightly thickens; 1-2 minutes. Add remaining 1 tablespoon butter and stir until well combined. Add worcestershire sauce and stir until blends with the onion mixture. Preheat oven to 400°F.
Add beef stock, thyme, bay leaf and pepper. Scrape the brown bits from the bottom and sides of the dutch oven. Bring the mixture to a boil. Lower to a simmer for 25 minutes. Stirring occasionally. Proceed with toasting bread.
Prepare French Bread Toast
Meanwhile, place slices of french bread on a baking sheet and brush the tops with olive oil. Toast for 4-5 minutes or until toasted throughout. Once cool to the touch, use one piece of garlic and grate over each bread’s tops. Set toasts aside.
Add fish sauce to the soup then season to taste with kosher salt, adjusting pepper to taste, if needed.
Broil French Onion Soup
Place oven-safe bowls on a baking sheet. Ladle soup into the bowls ¾ full. Top with toast then the cheese blend. Bake on BROIL for 3-5 minutes or until cheese is completely melted.
Remove from the oven and cool for 2 minutes. Top with fresh thyme (optional) and serve.
Tips and Tricks
- The key to the best French onion soup is time. There are no shortcuts when it comes to caramelizing onions. Caramelization occurs when the sugars in the onion reach a certain temperature. Patience will yield the best results. That’s where you’ll find the deep, distinct flavor you crave.
- Taste test store-bought broth before committing to it. If you don’t like the taste, do not use it in the soup. Keep in mind that all broths and stock are not alike and the broth or stock you use is important as it is the foundation of the recipe.
- Wondering how many servings this recipe yields? This soup can generously feed two as a main course or 4 if served as a side.
French Onion Soup Variations
- Vegetarian. Use vegetable broth instead of beef stock and omit the fish sauce and Worcestershire.
- Vegan. Make the changes suggested for the vegetarian version in addition to replacing butter with olive oil and using dairy-free cheese.
- Cheese. Feel free to swap out one of the cheeses for asiago, fontina, gouda, or mozzarella.
- Croutons. Instead of toast, you could make your own croutons. Wondering how to make croutons for french onion soup? the process is easy. Slice day-old bread into 1/2-inch cubes and sprinkle them with olive oil, salt, and pepper. Then bake them in an oven set to 350°F for about 30 minutes.
Store leftover soup (without the bread) in an airtight container in the fridge for up to 4 days. To reheat, bring it to a boil over medium-high heat then add freshly toasted French bread.
Can you freeze french onion soup?
Yes. Freeze french onion soup in an airtight container and it will last up to 3 months. If you have a lot left over, consider freezing individual servings. Let it defrost in the fridge overnight or submerge the sealed container in cool water for at least 30 minutes.
Uses for Leftover French Onion Soup
You can always reheat leftover soup but there are ways to repurpose it for new meals too. Here are my suggestions:
- Ladle out the onions and add them as a topping on smothered pork chops or chicken.
- Use the broth as a replacement for beef broth in various recipes.
- Add it to pasta and use it as a sauce.
Frequently Asked Questions
How do you deepen the flavor of french onion soup?
My personal go-tos include worcestershire sauce, fish sauce, and brandy. Each deepens the flavor of french onion soup. Balsamic vinegar and soy sauce are other great options.
What type of pot to use for french onion soup?
Use a large Dutch oven to prepare french onion soup. Even though the volume of the soup is not even close to 6 quarts, you want to use a pot that’s wide enough to allow for more surface to cook the onions and tall enough to hold the onions upon initially cooking.
How to cut onions for french onion soup?
Halve the onions then cut them into ¼-inch thick slices (from the top to the root). The onion will cook more efficiently with less surface area.
What to serve with french onion soup?
Although this soup can be enjoyed as a meal, it would be tasty with some sides. I suggest a light salad, mashed potatoes, a grilled cheese sandwich, or even a Croque Monsieur, depending on how big your appetite is.
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French Onion Soup
- 4 quart dutch oven
- Baking Sheet
- 3 Oven-Safe Bowls
- 2 tablespoons quality olive oil
- 2½ tablespoons salted butter
- 2 pounds yellow onion halved, cut into ¼-inch thick slices
- ½ pound sweet onion, halved, cut into ¼-inch thick slices
- 6 sprigs thyme
- ¼ cup brandy
- 1 cup dry vermouth, I use Lo-Fi brand, or Sauvignon Blanc
- 2½ teaspoons worcestershire sauce
- 2½ teaspoons fish sauce, plus more to taste, I use Three Crabs
- 1½ tablespoons fresh garlic, minced
- 1 large bay leaf
- 1 teaspoon kosher salt, plus more to taste, Diamond Crystal
- ½ teaspoon freshly cracked black pepper, plus more to taste
- 5½ cups homemade beef stock, or low sodium quality beef stock
- ½ baguette, cut into ½-inch thick slices
- olive oil
- large clove garlic, halved
For the Topping
- 1 cup gruyère cheese, freshly shredded
- ½ cup comté cheese, freshly grated
- chives (optional garnish), finely chopped
- Over medium heat, add the olive oil and butter. Once butter melts, add the onions and stir every few minutes. Do not rush this process; caramelizing onions takes 1 hour and 15 minutes to 1 hour and 40 minutes. As you cook the onions, take care to not let the mixture brown too quickly, rather it should slowly brown over time. If the mixture dries out, add 1½ teaspoons of water at a time and stir.
- Once the onions are deeply browned and caramelized, increase the heat to medium-high. Allow a brown glaze to slowly develop on the bottom of the pot. This is known as fond, which is key for flavor. Cook onions on medium-high heat for 2-3 minutes.
- Once onions are deep brown in color, and you have a nice brown fond, stir in the garlic. Cook for two minutes or until fragrant.
- Stir in the brandy, scraping the brown bits (fond) from the pot and cook until most of the liquid evaporates. Add dry vermouth or white wine and cook until the liquid reduces by about half, about 4 minutes.
- Add worcestershire sauce, fish sauce and ½ teaspoon black pepper. Stir to combine then add thyme sprigs and bay leaf. Add beef broth, bring to a boil then lower to a simmer. Cover with a lid, leaving a little crack, and cook for 40 minutes, stirring occasionally. While the soup cooks, Preheat oven to 400°F and toast the bread.
- Place slices of baguette on a baking sheet and top with olive oil. Bake for 5-8 minutes or until toasted and lightly browned. Remove from the oven and set aside.
- Adjust soup seasoning with more kosher salt and freshly cracked blacked pepper, if necessary. Switch oven temp to BROIL.
- Grate the tops of toasted bread with the fresh garlic, ensuring you get the corners really well. Pace oven-safe bowls on a baking sheet. Ladle soup into bowls. Top with garlic toasts and desired amount of gruyère and comté cheese. Transfer to the oven and bake until cheese completely melted and begins to slightly brown. Enjoy!