This easy French onion soup recipe, made from sweet caramelized onions in a flavorful broth, is one of the best winter meals. Make it ahead or freeze it whenever you need it!
Did I mention that this French onion soup is a dream? Slow-cooked onions caramelized to a deep mahogany, a splash of cognac and butter add classic richness, and lots of melted Gruyere might just bring you to your knees! Add a piece of toasted baguette to dip and it’s *chef’s kiss*.
This is a traditional French onion soup recipe, subbing the traditional use of beef broth with chicken broth. The use of chicken broth helps create a lighter, more delicate soup, with more focus on the sweetness of the caramelized onions.
Traditionally, French onion soup is served with toasted Baguette and topped with generous amounts of Gruyere. If you would prefer a more untraditional option, consider dipping with a Classic Grilled Cheese or even these Easy Yeast Rolls!
French Onion Soup Ingredients
- Low-sodium chicken broth – you can use either chicken broth or stock for the base of your soup. You can also use beef broth if preferred.
- Cognac – Cognac helps deglaze the pot after caramelizing the onions which also extracts and intensifies the flavors, adding depth to the soup.
- Yellow onions – Spanish onions are a larger, drier, and sweeter type of yellow onion. Since they contain less moisture, they caramelize faster! If you can’t find Spanish onions, substitute with regular yellow onions.
- Gruyere cheese – Gruyere cheese is a rich and flavorful cheese that is classically melted on top of the French onion soup, adding a savory element.
- Parmigiano-Reggiano – Parmigiano-Reggiano (or regular parmesan cheese if preferred) adds cheesy, nutty, saltiness that’s irresistible!
- Butter – butter adds richness and flavor!
- Baguette (optional)– the crisp and crunchy texture of a baguette is a wonderful contrast to the soup. Plus, it serves as the perfect dipping slice to make sure no drop of deliciousness is missed!
- Black pepper – black pepper adds a touch of heat and peppery flavor.
- Salt – salt enhances flavor.
How to Caramelize Onions
A crucial step to making this delicious French onion soup is transforming the onions from crisp and potent, to decadent and rich. Caramelizing is a relatively simple process and it doesn’t have to take hours to get the onions to the perfect mahogany brown. To begin caramelizing, add butter and onion strips to an extra-large pot. Leave the lid off, and turn the heat to medium-high. Allow the onions to cook down to about a third of their original size, tossing every few minutes. It may be more difficult to toss the onion in the beginning, but it should get easier as they cook down!
Once the onions cook down, keep heat at medium-high and let onions caramelize for 40-50 minutes until mahogany brown. Make sure to stir every few minutes.
French Onion Soup Tips
- Onions: slice onions thinly, about ¼ inch strips, so that they can caramelize efficiently to get to the best mahogany coloring without taking hours.
- Caramelizing: if the onions begin to burn, the heat is likely too high. Turn the heat down and add a splash of olive oil. On the other hand, if the onions are not almost done caramelizing after 40 minutes, the heat is likely too low.
- Serving: if you don’t have oven-safe ramekins, you can also serve the soup in regular bowls sprinkled with lots of Gruyere and a pinch of Parmigiano-Reggiano or regular parmesan. Then, you can toast a few pieces of baguette in the oven to dip into the soup!
How to Make French Onion Soup
Full instructions in the recipe card; this is just an outline!
- Caramelize.
Place butter and onion strips in a pot. Let the onions caramelize until they turn mahogany brown, stirring every few minutes for 40-50 minutes.
- Deglaze.
Deglaze the pot with cognac and then add chicken broth, pepper and salt. Stir again.
- Simmer.
Bring the soup to a boil, and then lower the heat to a simmer. Cover and let simmer for at least 10 minutes.
- Broil.
Place soup into oven-safe ramekins and then top with plenty of Gruyere and a pinch of parmesan. If you choose, place a piece of baguette on top of the soup. Broil until the cheese melts. Serve.
What to Serve with French Onion Soup
Depending on what you are serving French onion soup for, you may want to serve with a side dish or a delicious dipping option. Here are a few of my favorites!
Baguette: French onion soup pairs perfectly with a delicious baguette. My favorite is this easy and delicious Baguette recipe.
Salad: A simple green salad with a vinaigrette can provide a refreshing contrast to the richness of the soup. Consider using arugula like in this Crisp Apple Salad or Classic Italian Salad.
Vegetables: Adding a side of roasted vegetables like asparagus, Roasted Root Vegetables, or Sautéed Spinach will bring a variety of textures and flavors to balance the soup.
Quiche: Serve with a slice of quiche like Quiche Florentine or Cheesy Ham & Leek Quiche!
Grilled cheese: What pairs better with soup than a Classic Grilled Cheese? It’s the perfect dipping agent that makes sure you get every last drop.
More Soup Recipes You’ll Love!
How to Make French Onion Soup (Easy!)
Ingredients
- 32 ounces low-sodium chicken broth
- 50 mL cognac, 1 nip
- 8 large Spanish onions, cut into ¼ inch strips
- ¼ pound Gruyere cheese – sub Emmental or Jarlsberg cheese, grated
- ¼ pound Parmigiano-Reggiano or regular parmesan cheese grated
- 4 tablespoons butter
- Baguette (optional), cut into ½ inch slices
- ¼ teaspoon black pepper
- Salt, to taste
Instructions
- Place butter and onion strips in a pot. Let the onions caramelize until they turn mahogany brown, stirring every few minutes for 40-50 minutes.
- Deglaze the pot with cognac after the onions have turned a mahogany brown. Stir. Add chicken broth pepper, and salt. Stir again.
- Bring soup to a boil over high heat, then bring down to a simmer over low heat. Simmer, covered, for at least 10 minutes. I recommend simmering for at least 30 minutes for best results!
- Preheat oven to broil. Place soup in oven-safe ramekins. Rest a piece of baguette on the top of the soup. Add a generous amount of gruyere and a pinch of parmesan. Place in the oven on the broil setting for 2-5 minutes until the cheese melts and browns slightly. The baguette should be toasty. Serve with a big piece of baguette on the side!
Video
Notes
- Spanish onions are a larger, drier type of yellow onion. Since they contain less moisture, they caramelize faster! If you can’t find Spanish onions, you can substitute regular yellow onions. You may need to add in 2-3 extra onions if they are small. You also might have to increase the caramelization time by 10 minutes!
- If onions are burning, the heat is likely too high. Turn the heat down and add a splash of olive oil. If onions aren’t almost caramelized after 40 minutes, your heat is likely too low.
- If you don’t have oven-safe ramekins or bowls, go buy them! HA! Just kidding. You can also serve the soup in regular bowls sprinkled with lots of gruyere and a pinch of parm. You can toast a few pieces of baguette in the oven to dip into the soup!
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.