When the weather takes a turn, Classic French Onion Soup topped with cheesy croutons is comfort food that will hit the spot!

I tweaked my tried and true recipe by using two types of broth and adding some herbs. This was the Best French Onion Soup Recipe to come out of my kitchen! I bet you’ll love it as much as we did.

Classic French Onion Soup in a white ceramic soup bowl.

Why You Must Make

I adore baking, but I still have to get dinners ready for a family of 5, which is not nearly as much fun. When somebody actually requests a dish, I’m delighted to comply! My oldest recently asked if I could make French onion soup. So within days, it was on our menu.

  • If you’ve never caramelized onions, this recipe will prove their deliciousness.
  • The Gruyere-topped croutons are irresistible.
  • This is comfort food on a chilly day!

I slowly caramelized some thinly sliced Spanish onions along with a bit of minced garlic. A tablespoon of flour was sprinkled over them once they reached a golden brown color, and then dry white wine and broth were added. Bill and I picked up our youngest, Nick, from a 4-day retreat with his high school classmates, and the closing ceremony lasted well past our dinnertime. When we all arrived home, with who was sleep-deprived and in desperate need of a shower, we quickly rewarmed this aromatic soup, added a slosh of cognac, and broiled each bowl with a Gruyere-topped crouton.

My broiler was on the fritz (yes, my oven saga continues) so I didn’t get the golden crust I was hoping for but any melted cheese was better than none! It truly hit the spot on a cool autumnal evening.

Classic French Onion Soup topped with two slices of cheesy toasts.

Recipe Tips

French onion soup has always been a favorite. It’s all about the bread and gooey cheese topper. My favorite version to date is this combination of Dorie Greenspan’s and Thomas Keller’s recipes with a few tweaks of my own.

  • Taking time to fully caramelize the onions will magnify the delectable flavors. This is a slow process that takes patience but is worth the effort. Start with a sweeter onion, like the yellow onions I selected. They should slowly brown, but not burn, and must be stirred frequently. Well, caramelized onions give an amazing depth of deliciousness.
  • PRO-Tip: You can also caramelize onions in your slow cooker. All you’ll need is sliced onions and some canola oil. I might go with butter instead. So easy!
  • I added a bay leaf and a bit of fresh thyme to this French onion soup for another dimension. Layering flavors is key.
  • My best French onion soup is made with both beef and chicken broth from a box, but I’m certain it would be even more incredible with homemade stock. I prefer store-bought chicken broth to beef, but the combination is really nice.
  • Watch the sodium if you’re using some of those canned brands of broth or stock. Some are so salty that they can ruin your soup. I like using the Pacific brand which I’ve even seen at Target.
  • PRO-Tip: Did you know alcohol is a flavor enhancer? The deglazing of the pan with white wine and the addition of cognac both help make this an incredibly delicious soup.
  • PRO-Tip: Alton Brown added a teaspoon of fish sauce for the ultimate umami boost. It’s going in my next batch!
  • My favorite part of this dish is the cheesy crouton served on top of the soup! I toasted both sides of a long diagonal slice of a baguette in the oven, then placed one or two on the bowl of soup, and finally topped with a generous amount of shredded Swiss cheese.
  • Next, the soup bowls were popped under the broiler until hot, gooey, and golden! Gruyere is a classic cheese choice, but I love mixing half and half Gruyere and Emmenthal. More depth of flavor again!
  • My friend, Marissa, of Pinch and Swirl, cut her bread into croutons, so I followed suit with a few bowls. It was definitely easier to eat! She used Julia Child’s recipe if you want to peek at that, too.
Classic French Onion Soup in a white soup bowl with a bamboo handled spoon.

Frequently Asked Questions

Did French Onion Soup Originate in France?

Yes, it became popular in the 1800s in Les Halles, a Parisian open market. Restaurants in the area served their onion soup with a cheese topping that they placed under a grill to melt.

What Are the Best Onions for French Onion Soup?

Yellow onions are preferred since they are sweeter than white onions and caramelize beautifully. Red onions will alter the color of what’s considered classic for a French onion soup.

How Can You Boost the Flavor of Soup?

Make sure to season well with salt and pepper to suit your palate. Add herbs that complement your soup. Use flavor enhancers like alcohol, which if added early will evaporate, while bolstering the flavor. There are other sources of umami, or the savory sense of taste, like Worcestershire sauce, soy sauce, fish sauce, and even a Parmesan rind that provide nice flavor if they’re appropriate for your soup recipe.

You May Also Like

If you’re making a batch of caramelized onions for this onion soup, then why not toss in an extra onion and use the extras to enhance some other recipes!

Stay in touch through social media @ InstagramFacebook, and Pinterest. Don’t forget to tag me when you try one of my recipes! And if you love the results, please give it a 5-star rating in the recipe card.

Classic French Onion Soup - A rich onion laden broth flavored with herbs, white wine and cognac and topped with cheesy toast!

Classic French Onion Soup

Prep Time 15 minutes
Cook Time 1 hour
Total Time 1 hour 15 minutes
Yield 6 servings

A rich onion laden broth flavored with herbs, white wine and cognac and topped with cheesy toast!


  • 4 pounds yellow onions
  • 2 tablespoons butter
  • 2 tablespoons olive oil
  • 3-4 cloves of garlic, minced
  • Kosher salt
  • 1 tablespoon flour
  • 1 cup dry white wine (or vermouth)
  • 2 cups beef broth
  • 2 cups chicken broth
  • 2 bay leaves
  • 2 sprigs of fresh thyme
  • Freshly grated black pepper to taste
  • ¼ cup Cognac
  • 1 ½ cups grated Swiss cheese (I used half Gruyere and half Emmental)
  • Baguette, cut into ½ inch slices
  • Olive oil and kosher salt to toast baguette


  1. Peel onions, then cut in half through the root. Cut each half into thin slices. In a Dutch oven, heat olive oil and butter.
  2. Add onions, and garlic and sprinkle with Kosher salt. Slowly cook, over low heat, stirring frequently until
  3. the onions start to caramelize. Do not allow them to burn, but continue cooking till the onions are browned.
  4. When the onions are caramelized, add flour and cook for a minute or two to cook off the raw flour taste. Add wine or vermouth and reduce the liquid by about half.
  5. Add both types of broth, and bring to a boil. Reduce heat and allow soup to simmer for at least 30 minutes. Add cognac and stir. Check for seasoning, adding black pepper and more salt to taste if needed.
  6. Prepare croutons by brushing with olive oil and a sprinkle of Kosher salt. Broil till lightly toasted. Flip, brush with olive oil, and broil backside. Set aside. Watch carefully as these can burn quickly.
  7. Fill heat-proof bowls with soup, leaving room to top with crouton. Place crouton over soup and put about ¼ cup grated cheese over the toasts. Or like my friend, Marissa from Pinch and Swirl, make smaller croutons out of your slice and top those with cheese.
  8. Place bowls on a sheet pan and place under the broiler. Broil till cheese is melted, bubbly, and lightly brown. Serve immediately.


Deglazing the pan is key to building flavor. The alcohol will burn off, so it isn't a worry when serving it to children.

Adapted from recipes by Thomas Keller and Dorie Greenspan.

Nutrition Information:



Serving Size:


Amount Per Serving: Calories: 598Total Fat: 21gSaturated Fat: 9gTrans Fat: 0gUnsaturated Fat: 10gCholesterol: 37mgSodium: 1300mgCarbohydrates: 74gFiber: 7gSugar: 19gProtein: 21g


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