French Onion Soup
This post may contain affiliate links. Read my full disclosure policy. Warm, rich, and topped with golden, melty cheese, this French onion soup is pure comfort. From slowly caramelizing the onions to broiling the cheese, you’ll learn the essential steps to make this classic French recipe. French onion soup might be a staple on restaurant menus, but it started as a humble peasant dish made from just onions, stale bread, and water. Today, it’s a bit more refined but still wonderfully simple to make at home. The secret is patience: the onions need to be cooked low and slow until they’re sweet and caramelized. I like to add a touch of flour to thicken the broth slightly and finish the soup with two kinds of cheese—techniques I learned working in a restaurant renowned for its incredible French onion soup recipe. “I made this last night and it was amazing! I think it was even better than the French onion soup we had in Paris last summer.” Video Tutorial What You’ll Need To Make French Onion Soup Butter and vegetable oil: Used to caramelize the onions (the oil prevents the butter from burning). Vidalia (or sweet) onions: Lend a naturally sweet, mild flavor when caramelized. Sugar: Helps amplify the natural sweetness of the onions and aids in caramelization. Dry white wine: Deglazes the pan, dissolving the fond for a deep, complex flavor. All-purpose flour: Thickens the broth for a slightly hearty consistency. Beef broth: Forms the savory base of the soup, adding depth and richness. Worcestershire sauce: Enhances the umami flavor in the broth. Dried thyme and bay leaves: Infuse the broth with warm, earthy, and woodsy aromatics. Baguette: Serves as the base for the cheesy croutons. Dry sherry: Adds a layer of complexity and a slightly sweet, nutty finish to the broth. Gruyère cheese: Melts beautifully, creating a creamy, nutty topping. Look for an imported Swiss variety for the best flavor. Parmigiano Reggiano: Adds sharp, nutty depth to the cheesy topping. Jump to the printable recipe for precise measurements Butter and vegetable oil: Used to caramelize the onions (the oil prevents the butter from burning). Vidalia (or sweet) onions: Lend a naturally sweet, mild flavor when caramelized. Sugar: Helps amplify the natural sweetness of the onions and aids in caramelization. Dry white wine: Deglazes the pan, dissolving the fond for a deep, complex flavor. All-purpose flour: Thickens the broth for a slightly hearty consistency. Beef broth: Forms the savory base of the soup, adding depth and richness. Worcestershire sauce: Enhances the umami flavor in the broth. Dried thyme and bay leaves: Infuse the broth with warm, earthy, and woodsy aromatics. Baguette: Serves as the base for the cheesy croutons. Dry sherry: Adds a layer of complexity and a slightly sweet, nutty finish to the broth. Gruyère cheese: Melts beautifully, creating a creamy, nutty topping. Look for an imported Swiss variety for the best flavor. Parmigiano Reggiano: Adds sharp, nutty depth to the cheesy topping. Jump to the printable recipe for precise measurements Step-by-Step Instructions To begin, melt the butter in a large Dutch oven or soup pot. Add the oil, onions, salt, pepper, and sugar. Cook, stirring occasionally, until the onions are deep golden brown and caramelized, about 50 minutes. At this point, you’ll have beautifully caramelized onions. Pour in the wine and cook, stirring with a wooden spoon to loosen any browned bits from the pan, until the liquid is nearly evaporated and the onions turn jammy. Add the flour and stir for about one minute to dissolve. Add the broth, Worcestershire sauce, thyme, and bay leaves to the pot. Bring to a boil, then reduce the heat and simmer for about 30 minutes. Once done, add the sherry. While the soup simmers, place the baguette slices on a baking sheet. Bake until the bread is crispy and golden brown. Heat the broiler and place the crocks on a baking sheet. Pour the hot soup into the crocks and top with the baguette slices and cheese. Slide the crocks into the oven and broil until the cheese is bubbling and melted, a few minutes. Let the French onion soup crocks cool for a few minutes before serving. You May Also Like RecipeComments (255)Add Comment Recipe Comments (255) Add Comment Classic French Onion Soup Ingredients 4 tablespoons unsalted butter 1 tablespoon vegetable oil 3 pounds Vidalia (or sweet) onions (about 5 medium), halved lengthwise and thinly sliced ¾ teaspoon salt ½ teaspoon freshly ground black pepper ¾ teaspoon granulated sugar 1 cup dry white wine 2 tablespoons all-purpose flour 6 cups beef broth 1 teaspoon Worcestershire sauce ½ teaspoon dried thyme 2 bay leaves 1 small baguette, cut into ½-in slices 1 tablespoon dry sherry 8 ounces Gruyère cheese, grated (about 2 heaping cups; look for one imported from Switzerland) ½ cup grated Parmigiano Reggiano 4 tablespoons unsalted butter 1 tablespoon vegetable oil 3 pounds Vidalia (or sweet) onions (about 5 medium), halved lengthwise and thinly sliced ¾ teaspoon salt ½ teaspoon freshly ground black pepper ¾ teaspoon granulated sugar 1 cup dry white wine 2 tablespoons all-purpose flour 6 cups beef broth 1 teaspoon Worcestershire sauce ½ teaspoon dried thyme 2 bay leaves 1 small baguette, cut into ½-in slices 1 tablespoon dry sherry 8 ounces Gruyère cheese, grated (about 2 heaping cups; look for one imported from Switzerland) ½ cup grated Parmigiano Reggiano Instructions In a large Dutch oven or soup pot, melt the butter over medium heat. Add the oil, onions, salt, pepper, and sugar. Cook, uncovered, stirring occasionally with a wooden spoon, until onions are deep golden brown and caramelized, 45 to 55 minutes. In the beginning, you will only need to stir the onions occasionally. As they start to brown midway through cooking, you will need to stir them frequently, scraping the fond (the brown particles) from the bottom of the pan. If the onions are browning too quickly, reduce the heat slightly or add a few tablespoons of water to deglaze the pan and continue cooking. Add the wine and raise the heat to high. Cook, stirring with a wooden spoon to scrape any fond from the bottom of the pan, until almost all of the liquid has evaporated and the onions are jammy, 8 to 10 minutes. Add the flour and cook, stirring constantly, for one minute. Add the broth, Worcestershire sauce, thyme, and bay leaves to the pot. Bring to a boil, reduce the heat to a simmer, and cook, covered, for about 30 minutes. While the soup simmers, preheat the oven to 400°F and set an oven rack in the middle position. Arrange the baguette slices in a single layer on a baking sheet and bake until the bread is dry, crisp, and golden at edges, about 10 minutes. Set aside. When the soup is finished, remove the bay leaves and add the sherry; taste and adjust seasoning if necessary. If the soup needs a deeper flavor, try a few shakes of Worcestershire sauce. If it's not quite sweet enough, add ¼ teaspoon sugar. Adjust an oven rack 6 inches from the broiler element and heat the broiler. Place the oven-proof crocks on a baking sheet (see note below if you don’t have oven-proof crocks). Fill them with very hot soup, top each with 1 or 2 baguette slices without overlapping, and sprinkle evenly with Gruyère and Parmigiano Reggiano. Broil until the cheese is melted and bubbly around the edges, 3 to 5 minutes. Let the crocks cool for a few minutes before serving. Make-Ahead Instructions: The soup can be made and refrigerated up to 3 days ahead (without toasts or cheese), or frozen for up to 3 months. The toasts can be made (without the cheese) and kept sealed at room temperature for up to 3 days. Note: If you don’t have oven-proof soup crocks, place the toast slices on a baking sheet, top each with cheese, and broil for about 2 minutes, until the cheese is melted. Divide the hot soup among regular bowls and top each serving with the cheese toasts. In a large Dutch oven or soup pot, melt the butter over medium heat. Add the oil, onions, salt, pepper, and sugar. Cook, uncovered, stirring occasionally with a wooden spoon, until onions are deep golden brown and caramelized, 45 to 55 minutes. In the beginning, you will only need to stir the onions occasionally. As they start to brown midway through cooking, you will need to stir them frequently, scraping the fond (the brown particles) from the bottom of the pan. If the onions are browning too quickly, reduce the heat slightly or add a few tablespoons of water to deglaze the pan and continue cooking. Add the wine and raise the heat to high. Cook, stirring with a wooden spoon to scrape any fond from the bottom of the pan, until almost all of the liquid has evaporated and the onions are jammy, 8 to 10 minutes. Add the flour and cook, stirring constantly, for one minute. Add the broth, Worcestershire sauce, thyme, and bay leaves to the pot. Bring to a boil, reduce the heat to a simmer, and cook, covered, for about 30 minutes. While the soup simmers, preheat the oven to 400°F and set an oven rack in the middle position. Arrange the baguette slices in a single layer on a baking sheet and bake until the bread is dry, crisp, and golden at edges, about 10 minutes. Set aside. When the soup is finished, remove the bay leaves and add the sherry; taste and adjust seasoning if necessary. If the soup needs a deeper flavor, try a few shakes of Worcestershire sauce. If it's not quite sweet enough, add ¼ teaspoon sugar. Adjust an oven rack 6 inches from the broiler element and heat the broiler. Place the oven-proof crocks on a baking sheet (see note below if you don’t have oven-proof crocks). Fill them with very hot soup, top each with 1 or 2 baguette slices without overlapping, and sprinkle evenly with Gruyère and Parmigiano Reggiano. Broil until the cheese is melted and bubbly around the edges, 3 to 5 minutes. Let the crocks cool for a few minutes before serving. Make-Ahead Instructions: The soup can be made and refrigerated up to 3 days ahead (without toasts or cheese), or frozen for up to 3 months. The toasts can be made (without the cheese) and kept sealed at room temperature for up to 3 days. Note: If you don’t have oven-proof soup crocks, place the toast slices on a baking sheet, top each with cheese, and broil for about 2 minutes, until the cheese is melted. Divide the hot soup among regular bowls and top each serving with the cheese toasts. Nutrition Information Powered by Per serving (5 servings) Calories: 642 Fat: 31 g Saturated fat: 17 g Carbohydrates: 53 g Sugar: 19 g Fiber: 4 g Protein: 31 g Sodium: 1,697 mg Cholesterol: 82 mg Per serving (5 servings) Calories: 642 Fat: 31 g Saturated fat: 17 g Carbohydrates: 53 g Sugar: 19 g Fiber: 4 g Protein: 31 g Sodium: 1,697 mg Cholesterol: 82 mg This website is written and produced for informational purposes only. I am not a certified nutritionist and the nutritional data on this site has not been evaluated or approved by a nutritionist or the Food and Drug Administration. Nutritional information is offered as a courtesy and should not be construed as a guarantee. The data is calculated through an online nutritional calculator, Edamam.com. Although I do my best to provide accurate nutritional information, these figures should be considered estimates only. Varying factors such as product types or brands purchased, natural fluctuations in fresh produce, and the way ingredients are processed change the effective nutritional information in any given recipe. Furthermore, different online calculators provide different results depending on their own nutrition fact sources and algorithms. To obtain the most accurate nutritional information in a given recipe, you should calculate the nutritional information with the actual ingredients used in your recipe, using your preferred nutrition calculator. See more recipes: Freezer-FriendlyMake-AheadSoupsFrench Freezer-Friendly Make-Ahead Soups French