French Onion Soup

February 17, 2022

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The BEST French Onion Soup recipe! Made with slowly caramelized yellow onions, a savory lightly herby broth, and each serving is finished with golden brown, rich cheese toasts. Talk about delicious!

French onion soup shown in a white bowl with handles. Soup is topped with baguette slices, broiled cheese and herbs.

What is French Onion Soup?

Traditional French onion soup began as a humble peasant soup made with basic ingredients, and dates as far back as Roman times. It’s an onion and stock based soup served gratiné style with toasted bread or croutons and cheese atop.

It is one of those soups that you maybe didn’t appreciate as a child but have grown to really love an enjoy in all it’s cheesy flavorful glory as an adult.

While yes it is a rather easy soup to make and it doesn’t need very many ingredients, it does require a bit of time and tending to.

In other words patience is key. Have a little something to do nearby. Monitor the onions closely and you’ll have an excellent, deeply flavored bowl of soup to serve.

To ensure success be careful that you don’t burn and over-brown those onions or the frond (browned bits) on the surface of the pot (I’ve done this and it ruins the soup). Just monitor them as directed and deglaze the pot as directed.

And also don’t stop short of beautiful caramelized, this will take about 45 minutes, no shortcuts.

It’s all about slowly and gently caramelizing here. It’s a game changer.

As for the shade of the onions to watch for it’s all about a deep, richly golden brown color here (or even more so an auburn color) for the perfect soup.

Four servings of french onion soup in white bowls with handles, shown from overhead on a dark baking sheet.

French Onion Soup Recipe Ingredients

Soup Ingredients

  • 5 Tbsp unsalted butter, cut into 1-Tbsp pieces
  • 3 lbs yellow onions, peeled, halved and thinly sliced from root to tip
  • 1/4 tsp salt, then more to taste
  • 2 Tbsp all-purpose flour
  • 3/4 cup dry white wine, such as Sauvignon Blanc
  • 4 cups beef stock
  • 4 cups low-sodium chicken broth
  • 1 large sprig thyme
  • 2 bay leaves (fresh or dried)

Toast Ingredients

  • 12 (3/4-inch slices) baguette
  • 1 large garlic clove, halved
  • 1 1/2 cups shredded gruyere cheese
  • 1/2 cup finely shredded parmesan cheese
  • 1 Tbsp minced fresh parsley, optional

Photo of ingredients needed for french onion soup.

Best Type of Pot to Use for This Soup

  • I found a light colored cast iron pot works best for French Onion Soup. It is heavy and evenly distributes heat, and by using one with a light colored interior you can really see and monitor the shade of the onions.
  • Non-stick pots don’t caramelize as well or as evenly, plus any type of dark coated pot makes it hard to see the surface (which could have burnt browned bits). It’s also hard to track the shade of the onions caramelizing.
  • Many would say stainless steel works fine but for me personally it browned the onions too quickly and they ended up too dark.

Photo showing how to cut an onion.

How to Cut an Onion for This Soup

  • First trim a small portion from the top of the onion so it has a flat side to rest on to slice in half.
  • Then turn to that trimmed side facing down on the cutting board chop the onion in half from the root end to the top.
  • Cut each half portion into thin slices from top to root end, then trim away the root end.
  • Tip: I recommend using large onions in this soup. Less peeling and they’re easier to chop.

Collage of eight photos showing how to saute onions for french onion soup and the different shades they should reach to caramlize.

How to Make French Onion Soup

  • Melt butter in a large pot (about 6 quart) over medium heat.
  • Saute onions with a little salt, tossing occasionally until deeply golden brown, while also deglazing pot with a little water to scrape up browned bits on bottom so they don’t burn as needed. It will take about 45 to 50 minutes to caramelize onions.
  • Once onions are caramelized add flour and saute 1 minute.
  • Pour in white wine and scape up golden brown bits from bottom, and stir well to smoothly incorporate flour. Add beef stock, chicken broth, thyme and bay leaves season with salt and pepper and bring to a simmer over medium-high heat.
  • Reduce heat to low, cover and simmer 15 to 20 minutes.
  • Toast baguette slices: Meanwhile move oven rack about 6 inches from top element and preheat oven to 450 degrees. Rub garlic halves over one side of each baguette slice then align on a 18 by 13-inch rimmed baking sheet. Bake in preheated oven until slightly golden brown and crisp about 5 to 8 minutes.
  • Once soup is done, remove thyme and bay leaves.
  • Ladle soup into bowls on baking sheet: Preheat the oven to broil. Ladle soup into broil proof bowls filling no more than about 2/3 full (I used 20 oz bowls and added 1 1/2 cups soup).
  • Working with up to 4 bowls at a time place them on rimmed baking sheet (same one used to toast bread)
  • Top each soup with two baguette slices, gruyere and parmesan cheese then place about 6 inches from boiler on baking sheet and broil until cheese is nicely melted.
  • Serve right away garnished with parsley if desired.

Collage of eight photos showing french onion soup simmering then topping individual portions with cheese toast.

What is the Best Type of Onion for French Onion Soup?

  • Yellow onions are the best type of onion to use for this soup with their medium pungent flavor that ends up mellowing and caramelize beautifully without being overwhelmingly sweet.
  • Sweet onions aren’t recommended as they are more mild. They can also become too sweet once caramelized making them an inferior option.
  • Red onions and white onions can be sharper and spicer and a little harsh here.

Large white pot filled with french onion soup. A ladle is scooping soup and pot is resting on a wooden platter with a green cloth.

Helpful Tips and Common Questions

  • Making it with out wine: If you are looking for a version without using any alcohol then you can use more beef stock or chicken broth. Just note that if you choose to use the wine not all of the alcohol cooks out entirely, that is a common misconception.
  • Don’t have broil safe bowls: No problem. Simply add the cheese to the toasts on the baking sheet and broil them. Serve any extra cheese over the soup as well.
  • Gruyere substitute: For a cheaper alternative Swiss cheese is a great substitute to the Gruyere cheese.
  • Substitute for baguettes: If you don’t have a baguette you can use other rustic style bread, just slice into halves or quarters to fit into soup bowls.
  • Optionally add other herbs: A rosemary sprig or a few parsley stems would be a tasty addition.
  • Which kind of broth to use: I prefer the combo of beef stock and chicken broth here. Beef stock is traditional but chicken broth tastes better to me. You can just use one type you prefer though.
  • Making it vegetarian or vegan: If you are wanting to make it vegetarian replace beef stock and chicken broth with vegetable broth. For a vegan option you’d need to do that and also use a vegan butter and vegan cheeses.

French onion soup

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French onion soup shown in a white bowl with handles. Soup is topped with baguette slices, broiled cheese and herbs.
5 from 2 votes

French Onion Soup

The BEST French Onion Soup recipe! Made with slowly caramelized yellow onions, a savory lightly herby broth, and each serving is finished with golden brown, rich cheese toasts. Talk about delicious!
Servings: 6

Ingredients

Soup

  • 5 Tbsp unsalted butter, cut into 1-Tbsp pieces
  • 3 lbs yellow onions (preferably larger), peeled and thinly sliced
  • 1/4 tsp salt, then more to taste
  • Water, as needed (up to about 1/2 cup)
  • 2 Tbsp all-purpose flour
  • 3/4 cup dry white wine, such as Sauvignon Blanc
  • 4 cups beef stock
  • 4 cups low-sodium chicken broth
  • 1 large sprig thyme
  • 2 bay leaves (fresh or dried)

Cheese Toast

  • 12 (3/4-inch slices) baguette (about 9 oz)
  • 1 large garlic clove, halved
  • 1 1/2 cups shredded gruyere cheese, or Swiss cheese
  • 1/2 cup finely shredded parmesan cheese
  • 1 Tbsp minced fresh parsley, optional

Instructions

  • Melt butter in a large pot* (about 6 quart) over medium heat.
  • Add onions and salt and saute tossing occasionally, for 45 to 50 minutes - but keep reading and proceed with sauteeing process as noted. For the first 15 minutes toss about every 3 to 4 minutes. Reduce burner temperature to medium-low if onions are browning too quickly or browning along bottom of pot.
  • From here you'll need to cook about 30 minutes longer, and start tossing the onions more frequently about every 2 minutes then even down to every minute. As you toss the onions throughout the entire sautéing and caramelization process use a wooden or bamboo spatula to scrape up light browned bits from bottom of pot.
  • Also as you notice any light browning on the bottom of the pot that doesn't scrape up scoot the onions from that area, add a splash of water (about 1 Tbsp) then let it steam and scrape with the spatula (it can be scrapped into the onion mixture). This will really keep onion soup from tasting burnt.
  • Once onions are caramelized add flour and saute 1 minute.
  • Pour in white wine and scape up golden brown bits from bottom, and stir well to smoothly incorporate flour. Add beef stock, chicken broth, thyme and bay leaves, salt and pepper to taste and bring to a simmer over medium-high heat.
  • Reduce heat to low, cover and simmer 15 to 20 minutes.
  • Meanwhile move oven rack about 6 inches from top element and preheat oven to 450 degrees. Rub garlic halves over one side of each baguette slice then align on a 18 by 13-inch rimmed baking sheet. Bake in preheated oven until slightly golden brown and crisp about 5 to 8 minutes.
  • Once soup is done, remove thyme and bay leaves.
  • Preheat the oven to broil. Ladle soup into broil proof bowls filling no more than about 2/3 full (I used 20 oz bowls and added 1 1/2 cups soup).
  • Working with up to 4 bowls at a time place them on rimmed baking sheet (same one used to toast bread) top each soup with two baguette slices.
  • Sprinkle with plenty of the gruyere and parmesan cheese then place about 6 inches from boiler (still set on baking sheet) and broil until cheese is nicely melted.
  • Serve right away garnished with parley if desired.

Notes

  • I recommend using a heavy pot with a light colored interior so you can see when there is excess browning on the bottom of the pot to deglaze. I prefer an enameled cast iron pot rather than stainless steel or non-stick, onions don't burn as easily.
  • Recipe makes about 9 cups.
Nutrition Facts
French Onion Soup
Amount Per Serving
Calories 506 Calories from Fat 207
% Daily Value*
Fat 23g35%
Saturated Fat 13g81%
Trans Fat 1g
Polyunsaturated Fat 2g
Monounsaturated Fat 7g
Cholesterol 59mg20%
Sodium 906mg39%
Potassium 877mg25%
Carbohydrates 49g16%
Fiber 5g21%
Sugar 12g13%
Protein 23g46%
Vitamin A 809IU16%
Vitamin C 20mg24%
Calcium 456mg46%
Iron 3mg17%
* Percent Daily Values are based on a 2000 calorie diet.
Nutrition values are estimates only. See full disclaimer here.
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