Foolproof French Onion Soup | Buy This Cook That (2025)

Published: Mar 1, 2019 · Modified: Aug 8, 2022 by Buzzy · Buy This Cook That may earn a commission for purchases made after clicking links on this page. · 18 Comments

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 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 anduse Swanson® Beef Broth.

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.

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.

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.

See Also

French Onion Soup Recipe (VIDEO)Liver Pâté Recipe from The Food CharlatanCrispy Frizzled Onions from Scratch • Sunday TableCrispy Fried Onion Strings

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.

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.

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

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.

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 ¾ 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!

Click here to visit Swanson® for more recipes and inspiration using their line of products.

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