Foolproof French Onion Soup

This post is sponsored by Swanson®. All thoughts and opinions are my own.

Oh. My. Word. Get ready to sink your spoon into a rich bowl of this! Foolproof French Onion Soup turns out perfectly every time using a few basic ingredients. Loaded with savory, caramelized onions and flavored with hearty beef broth and white wine, this recipe is a hit with the whole family. Of course, you’ve gotta top it off with a thick slice of toasted, cheesy French bread, too. Want our recipe? You’ve got it, just keep reading. 🙂

Foolproof French Onion Soup | Buy This Cook That

Foolproof Cheesy French Onion Soup

French Onion Soup is one of the best soups of all time. Right up there with Chicken Noodle Soup, this recipe is a classic. The golden, savory onions simmered in delicious broth, flavored with just the right amount of tang with a good dry white wine…so good.

Just the kind of soup recipe you want to smother in cheese bread.

In this post, we are going to give you our recipe and tips to make the best French Onion Soup that turns out perfectly every time. All you have to do is follow the steps and use Swanson® Beef Broth.

Foolproof Cheesy French Onion Soup

Swanson® is a must-have in my kitchen. With no preservatives or artificial flavors, Swanson® Beef Broth is 100% natural. That makes me feel good about using it in my homemade recipes. From soups to stews to casseroles and more, this pantry staple adds so much depth and flavor to your food.

Ingredients Needed for this Recipe:

  • Yellow onions – A bunch of them! We used 7 yellow onions for this recipe, which yields about 8 cups sliced.
  • Swanson® Beef Broth – We used 6 cups of beef broth.
  • Dry white wine – Use a good quality, dry white wine like a Sauvignon Blanc or Pinot Grigio. This addition gives the French Onion Soup that signature pop of flavor.
  • Butter – You can use salted or unsalted, whatever you have on hand.
  • All-purpose flour – Just a few tablespoons of flour help thicken up the beef broth for the perfect consistency.
  • Brown sugar – We use a small touch of brown sugar in the onions, and we will tell you why.
  • Sea salt, black pepper, and a bay leaf – The seasonings are so simple.
  • French bread – No French Onion Soup is complete without it.
  • Gruyere + cheddar cheese – Oh yeah, this just got really good. Didn’t it?

How many of these ingredients do you have already? Have everything together? Great, time to get started.

TIP: I like to assemble all of my ingredients before I start cooking. That way, everything is easy to find and within reach exactly when I need it.

Foolproof French Onion Soup

With many soup recipes, you can toss everything into a pot and go. But the secret to the best French Onion Soup is in the cooking process. Let’s explain how.

How to Make Foolproof French Onion Soup:

  1. In a large pot, melt the butter over medium heat. Layer in the sliced onions and sprinkle with salt.
  2. Don’t touch the onions for 15 minutes. Resist the urge to stir! Let them do their thing and sweat down without disturbing them. The bottom will get a little brown. If you are worried about burning them, turn the heat down a little.
  3. After 15 minutes, reduce heat to low and stir in the brown sugar. The sugar helps them caramelize with a touch of sweetness. Cook and stir frequently for another 10 minutes until the onions are lovely and golden brown. (See pictures below for example.)
  4. Sprinkle the flour over the onions, and stir well until combined. The mixture will have a paste-like consistency. This is what you want. Cook and stir for another 3 – 5 minutes.
  5. Pour the white wine over the cooked onion mixture, scraping the brown bits from the bottom of the pot. (That brown is all buttery-oniony goodness.) Stir until the mixture is thick.
  6. Gradually add the beef broth, stirring well to combine after each addition. Add the bay leaf and pepper. This is where everything comes together!
  7. Heat to a low boil, stirring frequently. Reduce heat to a simmer and cook, stirring occasionally until the soup has thickened—about 15 minutes.
  8. Serve HOT with thick slices of toasted French bread topped with Gruyere and cheddar cheese.

Get the complete ingredient list and instructions in the recipe at the bottom of this post.

French Onion Soup

TIP: The secret to getting that heavenly onion flavor is in the cooking process. Don’t stir the onions for the first 15 minutes! Then, add a spoon of brown sugar, stir, and cook in the butter until perfect. Onions + butter + slow cooking = magic.

Foolproof Cheesy French Onion Soup

This recipe is so easy to make, and it tastes like you’ve been slaving in the kitchen all day. (Between you and me, it only takes about an hour.)

TIP: Time-saving idea: during the onion cooking process, double it. That’s right, double the onions, butter, salt, and brown sugar and make a double batch. Before moving on to the next step, transfer half of those gorgeous golden onions to a freezer safe container for next time. They will store in the freezer for up to 3 months, so you will have onions ready to go.

Foolproof French Onion Soup Recipe | Buy This Cook That

Anytime I make this French Onion Soup, I like to use a pot with a thick bottom, like a Dutch oven. It is easier to control the heat to ensure the onions don’t burn.

And we ALWAYS use Swanson® Beef Broth in this recipe. I don’t have to worry about the flavor or the seasoning because it is all there. Just open and pour.

Swanson's Beef Broth and French Onion Soup

Every ladle of our Foolproof French Onion Soup is loaded with authentic flavor—rich and savory. I’m ready for another bowl!

Savory Soups to Try:

Broccoli Cheddar Soup

Hearty + Healthy Cabbage Soup

Crockpot Lasagna Soup

Homemade Vegetable Soup

Foolproof Cheesy French Onion Soup | Buy This Cook That

Look how gorgeous this soup is. Can’t you smell it? The rich aroma of this soup will have everyone running to the kitchen, ready to eat.

Foolproof Cheesy French Onion Soup | Buy This Cook That

More Tips on Making Foolproof French Onion Soup:

  • Don’t rush the onions. You want them to slowly caramelize for the richest flavor.
  • Use more or less of the wine to your flavor preference. We used 3/4 cup for this recipe.
  • Try this recipe using red wine. It gives a deeper color and flavor that is delicious.
  • Warm up the broth before adding to the pot to speed up the cooking time.
  • This soup tastes even better the next day. Great for lunch!

French Onion Soup | Buy This Cook That

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Foolproof Cheesy French Onion Soup | Buy This Cook That

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Foolproof French Onion Soup
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5 from 2 votes

French Onion Soup

Delicious, savory, and so simple, this foolproof recipe for French Onion Soup is a family favorite. Made with caramelized yellow onions, beef broth, dry white wine and simple seasonings. Topped with toasted, cheesy bread.
Course Soup
Cuisine French
Keyword French onion soup
Prep Time 15 minutes
Cook Time 45 minutes
Total Time 1 hour
Servings 8 Servings
Calories 504kcal
Author Buy This Cook That


For the French Onion Soup

  • 4 tablespoons butter
  • 7 yellow onions peeled, halved, sliced (8 cups sliced)
  • 1 teaspoon sea salt
  • 1 teaspoon brown sugar
  • 4 tablespoons all purpose flour
  • 3/4 cup dry white wine
  • 6 cups Swanson® Beef Broth
  • 1 bay leaf
  • 1/2 teaspoon black pepper more to taste

For the Cheese Bread

  • 1 loaf French bread cut into 1 inch slices
  • 4 tablespoons butter or olive oil
  • 8 ounces Gruyere cheese sliced or shredded
  • 4 ounces cheddar cheese sliced or shredded


For the French Onion Soup

  • In a large pot or dutch oven, melt the butter over medium heat.
  • Layer in the sliced onions and sea salt and let cook WITHOUT stirring for 15 minutes. 
  • After 15 minutes have passed, reduce heat to medium low. Stir the brown sugar into the onions. 
  • Stir and continue to cook, stirring frequently, until the onions are golden brown, about 10 minutes.
  • Add the flour and stir into the onions. Cook and stir for 3 - 5 minutes until the flour is well incorporated and the consistency of paste. 
  • Pour the white wine over the cooked onion mixture, scraping the brown bits from the bottom of the pot. Stir until the mixture is thick.
  • Gradually add the Swanson® Beef Broth, stirring well to combine. Add the bay leaf and pepper.
  • Heat to a low boil, stirring frequently. Reduce heat to a simmer and cook, stirring occasionally, until the soup has thickened, about 15 minutes.

For the Cheese Bread

  • Turn on oven broiler. 
  • Lightly brush the sliced French bread with butter or olive oil. Arrange in a single layer on a baking sheet. Place under the broiler for 1 - 2 minutes until lightly toasted.
  • Remove the bread from the oven and evenly top each slice of bread with the two types of cheese. 
  • Return the bread to the broiler for another 1 - 2 minutes, watching carefully so it does not burn. The bread is done when the cheese is melted and the bread is browned.

To Serve

  • Ladle the prepared French Onion Soup into bowls. Top each bowl with prepared cheese bread, placing the cheese side up. Serve with additional pieces of cheese bread if desired.


Nutritional information may vary based on the type of bread and cheese used.


Serving: 1Bowl with 2 Slices of Cheese Bread | Calories: 504kcal | Carbohydrates: 41g | Protein: 21g | Fat: 26g | Saturated Fat: 16g | Cholesterol: 76mg | Sodium: 1505mg | Potassium: 354mg | Fiber: 2g | Sugar: 6g | Vitamin A: 760IU | Vitamin C: 7.1mg | Calcium: 449mg | Iron: 2.7mg


  1. Kelly says

    This did not turn out well at all. Against my better judgement I did the “cook for 15 minutes without stirring” on low heat- the butter burnt all on the bottom of my pan so I had to take the onions out and scrub the pan clean so I could save dinner (because I was making it for guests!) then pick all the burnt onions out. I thought id be good from here, but the amount of white wine in this made it taste terrible. I think I should’ve put half of what was called for. I had to add seasoning to hide the taste of the wine. I had such high hopes for this but I’m so disappointed in the taste and I’m thinking of just ordering out for our guests because I don’t want to serve them this. Not stirring something for 15 mins is just a guarantee you are going to burn it..

    • Teri says

      Kelly, I am terribly sorry you did not have a good result. I have made this recipe many times, and it works out for me and our taste. Regarding the onions cooking, I have them on VERY low heat, my lowest setting. I have an electric glass top oven…but I understand different stove tops may heat differently. The wine I add to my taste preference, I like the acidity in French Onion Soup. Again, I am sorry you didn’t have a good experience, but I sincerely appreciate your feedback. It helps me improve my recipes.

  2. Rachel says

    I made this today, absolutely delicious!!! I get a CSA box and had about 5 large onions. Low and slow cooking, for sure! The onions caramelized beautifully. I used a Pino Grigio 1/2 cup, some Tilamook Swiss sitting in my fridge looking lonely and Melba toasts. YUM! Even my 1 year old liked it. Bravo!

    • Teri says

      Great call on the Pinot Grigio (plus great for sipping, maybe?) Love Tilamook Swiss, too. Hard to go wrong. Your 1 year old has great taste.

  3. Kari says

    Just made it for dinner tonight, and the hole family loved it , awesome Recipe and it will be now a family favourite

  4. Ginger says

    I am making this right now! I HAD the onions on medium to start the 15 minutes…but then I read your response to the comment above and I turned it down a bit. I too have an electric smooth top oven…I will let you know how it turns out!!!!! I am optimistic!
    I don’t have white wine though…..hmmmm…I will figure something out

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