After many years making traditional French onion soup in restaurants, I’m finally sharing my recipe and step by step instructions on how to make French Onion Soup like a restaurant Chef! Made with caramelized onions, a rich savory broth and toasted cheesy bread, this flavorful soup is ridiculously easy to make, inexpensive and better than any store bought version out there!
Classic French Onion Soup Recipe at a Glance
- Main Ingredients: Caramelized sweet onions, savory beef broth, white wine, baguette slices, Gruyère cheese.
- Most Common Ingredient Substitution: You can substitute the wine with beef broth and the dry sherry with a tablespoon of cider vinegar.
- Dietary Information: This recipe is gluten-free adaptable and vegetarian adaptable.
- What You Need to Know: Cooking the onions over low heat, until they reach a deep golden brown color is an easy process that takes time and patience. The result is totally worth it.
- Most Common Mistake: Cooking the onions until dark brown will make the soup taste bitter. For best results, caramelize the onions until they are soft and golden brown.
Why this Easy French Onion Soup Recipe Works?
Sweet caramelized onions and good quality beef broth is what gives this classic French soup its rich flavor. To achieve extraordinary results, we cook the onions slowly to release their natural sugars and break down their intensity. The sweetness of the soft, caramelized onions enhances the broth giving it a depth of flavor that is impossible to reach any other way.
French Onion Soup ingredients
This is a partial list of ingredients needed to make this soup recipe. For the exact ingredients and amounts, please check the recipe card below.
- Onion: Although yellow onions are the ones I usually reach for, other kind of onions can be used to make this homemade French onion soup recipe! Sweet onions (such as Vidalia or Walla Walla) and white onions work very well also. Red onions can be used as well, although they have a mild bitter edge and are less sweet than the other varieties.
- Stock: Personally, I think nothing compares to the flavor of homemade beef stock, but more often than not I use store-bought beef broth. Beef broth is less meatier in taste than beef stock and lighter in texture. Although authentic French onion soup is always made with beef stock, chicken stock / chicken broth are a good substitution. Choose good quality, flavorful stock or broth.
- Butter and Oil: I use both ingredients to caramelize the onions. Oil prevents the butter from burning, and butter adds flavor. I use olive oil but other options are avocado oil, vegetable oil or canola. Unsalted or salted butter can be used.
- Worcestershire Sauce: Rich in umami, this ingredient adds deeper flavor to the soup.
- Wine: Traditionally, wine is used to make this soup recipe. Although the alcohol in the wine burns off completely, you can omit this ingredient and make French onion soup without wine. if using wine, dry white wine such as sauvignon blanc, pinot gris, chardonnay and other similar wines can be used. Red wine can be added. Choose one that doesn’t have a strong oak taste.
- Dry Sherry: The classic version of this soup is made with both white wine and dry sherry. Dry vermouth or brandy are good substitutions for the sherry. You can omit this ingredient if preferred but I suggest adding about a tablespoon of cider vinegar instead. The acid brings out the flavor of the rest of the ingredients
- Cheese: The classic option is Gruyere cheese. Other kind of cheese such as Fontina, Gouda, Swiss cheese or any other melty cheese can be used. A dusting of Parmesan cheese over the gooey cheese is always a fun idea.
- Bread: The cheesy toast on top of the soup definitely makes this, one of my favorite soups. French bread or baguettes are my go-to options.
Substitutions and Additions
- Replace the white wine with broth or stock if you prefer making this French onion soup recipe without wine.
- Replace the dry sherry with a tablespoon of cider vinegar or skip it all together.
- Use vegetable broth to make vegetarian French onion soup.
How to Make the Best French Onion Soup?
For detailed instructions and exact times, please check the recipe card below.
- In a large soup pot or Dutch oven, over medium heat, add oil and butter. When the butter has melted, add the onions, salt and black pepper.
- Cook, uncovered, stirring occasionally until the onions are caramelized and deep golden brown. Cooking the onions until they are dark brown will add a bit of a bitter taste to the soup.
- When the onions are caramelized, jammy and golden brown (see photo above), deglaze the pan by adding wine and dry sherry (if not using, replace the wine with broth/stock and the dry sherry with cider vinegar). Scrape the browned bits at the bottom of the pot with a wooden spoon. Cook until almost all the liquid has evaporated.
- To make a roux, which thickens the soup, add the flour and cook, stirring constantly for about 1 minute or until all of the flour is mixed in.
- Slowly add a cup of broth while stirring constantly. Stir in the remaining broth, bay leaf, fresh thyme and Worcestershire sauce. Bring to a boil, then reduce the heat and simmer for about 20 minutes.
- While the soup simmers, preheat the oven to 400ºF. Place bread slices in a single layer on a baking sheet and bake until the bread is crisp and golden on the edges.
- To broil the cheese topping, turn on the broiler.
- When the soup is done simmering, divide the soup among oven-proof soup bowls. Top each bowl of soup with a piece of toasted bread.
- Sprinkle generously with Gruyere cheese.
- Broil until the cheese is melted, bubbly and starts browning around the edges.
Tips for Making the Best Onion Soup
- Caramelizing Onions: This is a very easy job but it takes time and some patience. Don’t rush the process! For best flavor, it’s important to cook the onions low and slow. Exact cooking times vary, depending on the size and the type of the pot you are using, and the type of onions.
- Sugar: A lot of recipes for caramelizing onions include sugar. Sugar is actually not necessary to get the onions golden brown with a jam-like consistency. All that is needed is the proper amount of heat and time. If preferred, you can sprinkle about 1 teaspoon of granulated sugar to the onions when you start cooking them.
- No Oven-Safe Soup Bowls? No Problem!: If you don’t have oven-safe soup bowls, place the sliced bread on a baking sheet. Bake the bread until lightly toasted. Top the toasted bread with cheese and bake it until the cheese is melted. Remove from the oven and transfer the cheesy toasts to the top of the soup bowls. Serve.
- Prevent the Cheese from Sinking: Toasting the bread before topping it with cheese has a double purpose. First, it prevents the cheese from sinking like the Titanic, quickly. Second, it adds a bit of crunch to the soup topping.
- Serve Immediately: To best enjoy this soup, serve it right after broiling the cheese. When the soup sits for too long, the bread gets very soft and the cheese starts to sink in.
- Make it Ahead: You can caramelize the onions and make the soup 2-3 days ahead of time. Keep it refrigerated. When ready to serve, reheat the soup on the stove top until warm through. Toast the bread, top it with cheese, broil and serve immediately.
Frequently Asked Questions
What Type of Onions Should I Use to Make This Soup?
French onion soup can be made with any type of onion, although in my opinion it’s best when made with yellow onions. Sweet onions such as Vidalia make a great French onion soup also.
Can I Make French Onion Soup Without Wine?
Yes! French onion soup can definitely be made without wine or any other alcoholic beverage (dry sherry or vermouth). Replace the wine with additional broth and add 1 tablespoon of cider vinegar instead of the dry sherry. The acidity in the vinegar adds a sharp edge that deepens the flavor of the soup.
What’s the Secret to Making Caramelized Onions Properly?
To get onions caramelized properly, all you need is moderate heat, time and patience. Taking the time to cook the onions slowly, without rushing the process makes a big difference. Stirring frequently and making sure the heat is low enough to cook the onions without scorching them is also important.
What Broth is French Onion Soup Made From?
Classic French Onion Soup is made with beef broth. Although homemade beef broth (or beef stock) is best, store-bought can be used. The flavor of canned or boxed beef broth / beef stock, varies greatly from brand to brand. Some are a bit bitter and not very flavorful. If you cannot find a beef broth that you like, it’s best to use chicken broth instead. To make vegetarian French onion soup, use vegetable broth. As for low-sodium or regular broth, choose the one you prefer.
What’s the Difference Between Broth and Stock?
- The main difference between stock vs broth is their primary ingredient. Stock is made by simmering animal bones, vegetables, aromatics and fresh herbs in water, for several hours. Broth on the other hand, extracts its flavor mostly from meat, although it can contain some bones plus the other ingredients found in stock. When making stock, bones are usually roasted in the oven first. This step adds color and deepens the flavor.
- The collagen and the proteins extracted from the bones makes the stock rich and thick. Broth on the other hand is lighter in texture.
- Salt is never added when making stock while broth sometimes contains salt as seasoning.
Why is my French Onion Soup Bitter?
- Bitterness in this soup comes from overcooking or burning the onions. The caramelized onions should be deep golden brown, not dark brown. While cooking the onions, it’s important to stir them to prevent them from sticking to the pot and/or burning. Remember, slow cooking and moderate to low heat is essential for success.
- Another reason why French onion soup can become bitter, is the broth. Some store-bought brands are strong and bitter. If you cannot find a flavorful beef broth, using chicken broth or stock is your best option.
- Too much of a good thing can be bad. This is the case when using too much Worcestershire sauce. You can overdo it and bring some bitterness to the soup.
Is French Onion Soup Thick or Thin?
This soup is made with a roux (a combination of butter/oil and flour) which thickens the broth slightly. It should not be the consistency of stew but a bit thicker than plain broth.
Can I Make French Onion Soup without Beef Broth?
Yes! French onion soup can be made with chicken broth or chicken stock. You can also make vegetarian French onion soup with vegetable broth.
What’s the Best Cheese for this Soup?
Traditionally, French onion soup is made with Gruyere cheese although any cheese that melts well can be used. Fontina cheese and mozzarella are good options.
Is French Onion Soup Gluten-Free?
Although authentic French onion soup recipe is not gluten-free, it can be easily adaptable. To make gluten free French onion soup, use gluten free flour and gluten free bread.
Make Ahead, Storing, Freezing and Reheating
- To make ahead, cook the soup all the way but don’t add the topping. Refrigerate the soup for 2-3 days.
- Leftover French onion soup (with the cheesy bread topping), can be kept in the fridge in an airtight container for 2-3 days. Keep in mind that the bread will get soggy and sink.
- French onion soup freezes well without the bread and cheese topping. Store in a freezer-safe resealable bag or airtight container for up to 3 months. Thaw out in the fridge overnight.
- Reheat the soup on the stovetop until warm through. Then proceed toasting the bread, serving the soup in oven-safe bowls, topping the soup with the toasted bread slices and cheese. Broil and serve.
Take a Look at These Other Deliciously Easy Soup Recipes
- Thai Tom Yum Soup
- Albondigas Soup (Mexican Meatball Soup)
- Creamy Roasted Cauliflower Soup
- Chicken Tortilla Soup Recipe
- Easy Mediterranean Style Chickpea Soup Recipe
- Roasted Garlic Potato Soup (Česnecka)
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French Onion Soup
- 4 tablespoons butter (unsalted or salted)
- 1 tablespoon olive oil or vegetable oil
- 3 pounds onions (see notes) peeled, halved and thinly sliced (about ⅛-thick) yellow onions or sweet Vidalia onions work best
- ¾ teaspoon Kosher or sea salt plus more to taste
- ¼ teaspoon freshly ground black pepper plus more to taste
- 3/4 cup dry white wine (replace with broth if preferred)
- 1 tablespoon dry sherry (replace with cider vinegar if preferred)
- 2 tablespoons all-purpose flour
- 8 cups beef broth or beef stock
- 1 bay leaf
- 2 fresh thyme sprigs or ½ teaspoon dried thyme
- ½ teaspoon Worcestershire sauce
- 1 small baguette sliced ½-inch thick
- 6 ounces Gruyère cheese, grated (about 1 ½ cups) (replace with Fontina or Mozzarella)
- Optional: Garnish with fresh thyme leaves or chopped chives.
- In a large pot or Dutch oven, over medium heat, add the oil and butter. When the butter has melted, add the onions, salt and black pepper. Stir.
- Cook, uncovered, stirring occasionally until the onions are caramelized and deep golden brown, about 45 to 55 minutes. Times vary depending on the size and type of pot you are using and the amount of heat. Midway through the cooking process, you may need to stir more frequently. If the onions are browning too quickly, lower the heat as needed. If the onions are sticking to the pot, scrape the bottom of the pot with a wooden spoon. If needed, deglaze the pot by adding about a tablespoon of water and scraping the bottom.. This will help release the bits that are stuck. Continue cooking.
- When the onions are caramelized and golden brown, add the wine and the dry sherry. Raise the heat to medium high and bring to a boil. Cook until almost all the liquid has evaporated, about 5-6 minutes. Add the flour and cook, stirring constantly for about 1 minute.
- Slowly add a cup of broth while stirring constantly. Stir in the remaining broth, bay leaf, thyme and worcestershire sauce. Bring to a boil, then reduce the heat and simmer for 20 minutes.
- While the soup simmers, preheat the oven to 400ºF. Set the oven rack in the middle position. Place bread slices in a single layer on a sheet pan and bake until the bread is crisp and golden on the edges, about 8-10 minutes.
- When the soup is done simmering,remove the bay leaf and thyme sprig. Taste and adjust seasoning (please see Chef’s notes).
- To broil the cheese topping, set an oven rack about 6-inches below the heat source. Turn on the broiler (on low or high).
- Arrange individual ovenproof soup bowls or individual casseroles on a baking sheet. Divide the hot soup among the bowls.Cover the top with bread slices (1-2 slices depending on size). Make sure the bread doesn’t overlap. Sprinkle generously with Gruyere cheese.
- Broil until the cheese melts and starts browning around the edges. Watch it carefully as the broiler browns things quickly.
- If you don’t have any ovenproof soup bowls, top the toasted bread with cheese and broil until melted and bubbly. Top each soup bowl with some cheese toasts.
- Onions come in many sizes so it’s hard to figure out how many onions come in a 3 pound bag; however, a large onion the size of a softball can weigh 8 to 10 ounces each. Medium onions the size of a baseball or orange can weigh 6 to 8 ounces each.
- Because all onions are not created equal, you may need to make some adjustments to the seasonings to your taste.
- For deeper flavor, add a few dashes of Worcestershire sauce.
- For a boost of flavor, add about 1 teaspoon of beef bouillon.
- If it tastes a bit bitter, add a ¼ to ½ teaspoon of sugar.
- Make sure the soup is hot when you pour it into the ovenproof bowls for broiling.
- The alcohol in the wine and sherry completely cooks off, making this a family-friendly meal.
- If preferred, substitute the wine with additional broth and the dry sherry with cider vinegar to make French Onion Soup without wine (or any alcohol).
- Make vegetarian French onion soup by using vegetable broth.
- Chicken broth can replace the beef broth.