French onion soup is easy to make, but it takes time and patience. You can’t rush caramelizing onions. This delicious soup is best made with a partner, serve up your favorite beverage, and take it slow. Your patience will be rewarded with a delicious soup that’s worthy of a special occasion.
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- Oil – We cook the onions in olive oil and butter. Use your your favorite oil that is suitable for sautéing.
- Onions – Yellow onions are preferred for this recipe, but white onions will work well too.
- Wine – White wine is used to deglaze the pot after caramelizing the onions. If you’re not a big wine drinker and hate opening a whole bottle to use ½ cup (I know I do), large, mainstream wine companies make small bottles of wine, like for picnics. They come in four packs and are the perfect size.
- Broth – Beef broth is the standard but chicken broth and vegetable broth will work too.
- Herbs and spices – The flavor of the onions and broth are enhanced with a bay leaf, fresh thyme, salt (we use kosher salt), and fresh ground black pepper.
- Bread – Use a French baguette, or substitute with another type of crusty bread.
- Cheese – Gruyere, provolone, Swiss will work well. In a pinch you can use gouda and mozzarella cheese (not fresh mozzarella).
- See recipe card for quantities
Use gentle heat, keep the onions on moderate (medium) heat the whole time. You can’t rush this process, do not crank the heat.
Stir the onions often, especially when they start to caramelize. Keep stirring and gently scraping the bits that are stuck to the bottom of the pot.
Deglaze the pot with broth if you do not use wine. Follow the same instructions using broth instead of wine.
Heat the olive oil and butter in a large pot over medium heat. When the butter is melted and foaming, add the sliced onions. It will look like there are too many onions, but they will reduce significantly as they cook.
Stir the onions occasionally at first. As they begin to turn a soft caramel color start stirring more often to prevent them from burning on the bottom.
The onions when they are first added to the pot.
After 15 minutes the onions have started to reduce in volume.
After 25 minutes there is a noticeable reduction, plus they are starting to turn a soft golden color.
The onions will continue to reduce and caramelize. At this point stir frequently, almost constantly.
After 45-50 minutes the onions have turned a rich golden-brown color. The brown bits on the bottom of the pot are sweet caramelized onions. If they sit there too long they will become burnt and will be bitter.
- Next, add the white wine to the pot. Gently scrape any bits off the bottom of the pot.
- Cook the wine with the onions for 1-2 minutes or until most of the liquid has cooked out.
- Add the beef broth, bay leaf, thyme, salt, and pepper to the pot. Stir well.
- Raise the heat to medium-high and bring the onion soup to a simmer. Then, lower the heat to medium-low, cover and cook for 20 minutes to let the flavors come together, stir occasionally. Keep the liquid at a simmer, if it’s boiling too vigorously, lower the heat.
Build the soup
- Preheat the oven to 250°F. Slice the bread into ½-1 inch rounds. Lightly toast the bread, about 5-7 minutes.
- When the soup is done, take the pot off the heat and discard the bay leaf and thyme. Use tongs to fish them out.
- Taste the onion soup and add a salt if needed. As a reference, we did not add any extra salt to ours.
- Preheat oven to the broil setting. Ladle the soup into individual, broiler safe bowls (like a soup crock or ramekin).
- Place one or two slices of bread on the soup depending on the size of the bowl. Place a slice or two of cheese on the bread.
- Place the bowls on a baking sheet to prevent the cheese from melting all over your oven. Plus, it makes getting the bowls in and out a lot easier.
Broil until the cheese is melted and becomes golden in spots. This step will only take a few minutes. Check them every minute and don’t leave the oven’s side. Turn on the oven light and keep a close eye on the cheese to make sure it doesn’t burn.
Onion soup takes some time to make, plus everything including you and your house will smell like onions. If you want to make the soup for a dinner party, make it a day ahead and refrigerate in an airtight container. The day of the party, gently heat it to a simmer. Then build it as instructed.
Serving and storing
Garnish the soup with fresh thyme or some chopped parsley, if desired, serve and enjoy.
Only prepare the needed servings with bread and cheese. Store leftover soup in an airtight container and refrigerate for 3-4 days. Freeze the soup for 2-3 months. Leave 1-2 inches of space in the container to allow for expansion when freezing.
Reheat the soup in a saucepan or the microwave until hot and steamy (temperature of at least 165°F).
Frequently asked questions
Traditionally, yellow onions are used, however, both yellow and white onions work well.
The classic cheese used is Gruyére, but Swiss and provolone cheese make suitable alternatives
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French Onion Soup
- 2 tablespoons Olive Oil
- 2 tablespoons Butter
- 3 pounds Yellow Onions peeled, halved, and sliced into ¼ inch thick pieces
- ½ cup White Wine
- 6 cups Beef Broth or substitute chicken broth, or vegetable broth, if needed
- 1 Bay Leaf
- 3-4 Thyme Sprigs tied together with kitchen twine for easy removal
- ½ teaspoon Salt plus extra if needed at the end
- ¼ teaspoon Black Pepper
- Crusty French Baguette sliced into ½-1 inch thick rounds and lightly toasted
- 6-8 ounces Gruyére Provolone or Swiss Cheese (4-8 slices – if the slices are thin, double up)
- Heat the olive oil and butter in a large pot over medium heat. When the butter is melted and foaming, add the sliced onions.
- Cook the onions for 45-50 minutes. Stir the onions occasionally at first. As they begin to turn a soft caramel color (after 15 minutes or so) start stirring them more often to keep them from burning.
- After approximately 25 minutes stir the onions almost constantly and gently scrape any bits off the bottom of the pot. After 45-50 minutes they should be a rich golden color.
- Add the white wine and stir while gently scraping any bits off the bottom of the pot. Cook the wine with the onions for 1-2 minutes or until most of the liquid has cooked out.
- Add the beef broth, bay leaf, thyme, salt, and pepper to the pot and stir well.
- Raise the heat to medium-high and bring the onion soup to a simmer. Lower the heat to medium-low, cover and cook for 20 minutes, stirring occasionally. Keep the soup at a simmer, if it’s boiling too vigorously, lower the heat.
While the soup cooks
- Preheat the oven to 250°F. Bake the bread for 5-7 minutes until lightly toasted.
- When the soup is done, take the pot off the heat and discard the bay leaf and thyme.
- Taste and add salt if needed. As a reference, we did not add any extra salt to ours.
Build the French onion soup
- Preheat oven to the broil setting.
- Ladle the soup into individual, broiler safe bowls (like a soup crock or ramekin). Place one or two slices of bread on the soup (depending on the size of the bowl). Place a slice or two of the cheese over the bread.
- Set the bowls on a baking sheet; this will prevent the cheese from melting all over your oven. Plus, it makes getting the bowls in and out a lot easier.
- Broil the French onion soup until the cheese is melted and becomes golden in spots. This step will only take a few minutes. Check on them every minute until they reach the desired color.
- Get everything ready to go for this soup before starting. Once you get to the point where you need to stir almost constantly, there won’t be any more time for prep.
- If you don’t drink wine, deglaze to the pot with broth, follow the same instructions above.
- Do not slice the onions too thin or they will disintegrate during the caramelizing process.