Best French Onion Soup

This Best French Onion Soup is a cozy, bistro‑style classic with deeply caramelized onions, a rich, savory broth, and a golden, bubbly Gruyère crust. It’s slow-simmered for layers of flavor, finished with a splash of wine and brandy, and served with toasted baguette for the ultimate comfort in a bowl.

Ingredients

• 1 tablespoon olive oil
• 2 tablespoons unsalted butter
• 5–6 large yellow onions, thinly sliced
• 1 teaspoon sugar
• 1 teaspoon salt, plus more to taste
• 2 cloves garlic, minced
• 2 tablespoons all-purpose flour
• ½ cup dry white wine (optional but recommended)
• 6 cups beef stock or beef broth, preferably low-sodium
• 1 teaspoon fresh thyme, or ½ teaspoon dried
• 1 bay leaf
• ½ teaspoon black pepper
• 1 tablespoon brandy or sherry (optional, traditional touch)
• For Serving
• Baguette slices, toasted
• 1½–2 cups Gruyère cheese, freshly grated

Instructions

1. Caramelize the onions: Heat the olive oil and butter in a large heavy pot over medium heat. Add the sliced onions, sugar, and salt. Cook, stirring frequently, for 30–40 minutes until the onions are very soft, deeply golden, and caramelized. Adjust the heat as needed so they brown slowly without burning.
2. Add garlic and flour: Stir in the minced garlic and cook for 1 minute until fragrant. Sprinkle the flour over the onions and cook, stirring constantly, for 2–3 minutes to remove the raw flour taste.
3. Deglaze with wine: Pour in the dry white wine, scraping up any browned bits from the bottom of the pot. Simmer for 2–3 minutes until slightly reduced.
4. Simmer the soup: Add the beef stock, thyme, bay leaf, and black pepper. Bring to a gentle simmer and cook uncovered for about 30 minutes to let the flavors meld.
5. Finish and season: Remove and discard the bay leaf. Stir in the brandy or sherry if using. Taste and adjust with more salt and pepper as needed.
6. Prepare the topping: Preheat the oven to 400°F (205°C). Ladle the hot soup into oven-safe bowls set on a baking sheet. Top each bowl with toasted baguette slices and a generous handful of grated Gruyère.
7. Broil: Transfer the baking sheet to the oven and broil for 2–4 minutes, watching closely, until the cheese is melted, bubbly, and lightly browned. Serve hot.

Variation

1. Use chicken or vegetable broth instead of beef for a lighter flavor; add a teaspoon of soy sauce or miso for extra depth if using veg broth.
2. Make it extra cheesy by mixing Gruyère with a bit of Comté, Swiss, or mozzarella for an extra-melty, stretchy topping.
3. Turn it into a main course by adding shredded cooked beef or rotisserie chicken to the soup during the last 10 minutes of simmering.

Cooking Notes

1. Onion choice matters: yellow onions are classic, but a mix of yellow and sweet onions adds complexity.
2. Control the heat while caramelizing: if onions start to scorch, lower the heat and add a splash of water to deglaze.
3. If the soup tastes flat, it usually needs more salt or a small splash of acid (wine, brandy, or a squeeze of lemon).

Serving Suggestions

1. Serve with a simple green salad dressed in a light vinaigrette to balance the richness.
2. Pair with a glass of dry white wine, light red wine, or sparkling water with lemon.
3. Offer extra toasted baguette on the side for dipping into the broth and melted cheese.

Tips

• Slice the onions as evenly as possible so they caramelize at the same rate.
• Grate the cheese fresh pre-shredded cheese often contains anti-caking agents that prevent smooth melting.
• Place the soup bowls on a baking sheet before broiling to catch any drips and make them easier to transfer in and out of the oven.

Prep Time

• Prep Time: 20 minutes
• Cook Time: 50–60 minutes
• Total Time: 1 hour 10 minutes–1 hour 20 minutes

Nutritional Information (Per Serving)

• Calories: Approx. 420
• Protein: Approx. 18 g
• Sodium: Approx. 980 mg

Frequently Asked Questions

1. Can I make French onion soup ahead of time?
   – Yes. Make the soup through the simmering step, cool, and refrigerate for up to 3 days. Reheat on the stove, then add the bread and cheese and broil just before serving.
2. Can I freeze French onion soup?
   – The soup (without bread and cheese) freezes well for up to 3 months. Thaw in the fridge overnight, reheat gently, then finish with baguette and Gruyère under the broiler.
3. What if I don’t have oven-safe bowls?
   – Broil the baguette slices topped with cheese on a baking sheet, then float them on top of each bowl of hot soup right before serving.
4. Do I have to use wine and brandy?
   – No, but they add classic depth. If skipping alcohol, use a bit more broth and finish with a squeeze of lemon or a splash of vinegar to brighten the flavor.

Conclusion

This Best French Onion Soup delivers everything you want in a classic: deeply golden onions, a silky, savory broth, and that irresistible cap of toasted baguette and gooey Gruyère. It’s simple, slow cooking at its finest perfect for cozy nights, dinner parties, or anytime you’re craving true French bistro comfort at home.

Best French Onion Soup

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• Author: ChefSophia
• Total Time: 1 hour 10 minutes–1 hour 20 minutes
• Yield: 4–6 servings 1x
• Diet: Omnivore

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Description

This Best French Onion Soup is a cozy, bistro‑style classic with deeply caramelized onions, a rich, savory broth, and a golden, bubbly Gruyère crust. It’s slow-simmered for layers of flavor, finished with a splash of wine and brandy, and served with toasted baguette for the ultimate comfort in a bowl.

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Ingredients

Scale 1x2x3x

• 1 tablespoon olive oil
• 2 tablespoons unsalted butter
• 5–6 large yellow onions, thinly sliced
• 1 teaspoon sugar
• 1 teaspoon salt, plus more to taste
• 2 cloves garlic, minced
• 2 tablespoons all-purpose flour
• ½ cup dry white wine (optional but recommended)
• 6 cups beef stock or beef broth, preferably low-sodium
• 1 teaspoon fresh thyme, or ½ teaspoon dried
• 1 bay leaf
• ½ teaspoon black pepper
• 1 tablespoon brandy or sherry (optional, traditional touch)
• For Serving
• Baguette slices, toasted
• 1½–2 cups Gruyère cheese, freshly grated

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Instructions

1. Caramelize the onions: Heat the olive oil and butter in a large heavy pot over medium heat. Add the sliced onions, sugar, and salt. Cook, stirring frequently, for 30–40 minutes until the onions are very soft, deeply golden, and caramelized. Adjust the heat as needed so they brown slowly without burning.
2. Add garlic and flour: Stir in the minced garlic and cook for 1 minute until fragrant. Sprinkle the flour over the onions and cook, stirring constantly, for 2–3 minutes to remove the raw flour taste.
3. Deglaze with wine: Pour in the dry white wine, scraping up any browned bits from the bottom of the pot. Simmer for 2–3 minutes until slightly reduced.
4. Simmer the soup: Add the beef stock, thyme, bay leaf, and black pepper. Bring to a gentle simmer and cook uncovered for about 30 minutes to let the flavors meld.
5. Finish and season: Remove and discard the bay leaf. Stir in the brandy or sherry if using. Taste and adjust with more salt and pepper as needed.
6. Prepare the topping: Preheat the oven to 400°F (205°C). Ladle the hot soup into oven-safe bowls set on a baking sheet. Top each bowl with toasted baguette slices and a generous handful of grated Gruyère.
7. Broil: Transfer the baking sheet to the oven and broil for 2–4 minutes, watching closely, until the cheese is melted, bubbly, and lightly browned. Serve hot.

Notes

• Take your time with the onions—true caramelization can take 40 minutes or more.
• Low-sodium broth lets you control the salt level at the end.
• If you skip the wine and brandy, add a squeeze of lemon or a splash of vinegar to brighten the flavors.
• Use oven-safe bowls or crocks that can handle broiling.
• Soup can be made ahead; add bread and cheese just before serving and broil.

• Prep Time: 20 minutes (plus 30–40 minutes to caramelize onions, overlapping with cook time)
• Cook Time: 50–60 minutes
• Category: Soup
• Method: Stovetop & Broil
• Cuisine: French

Nutrition

• Serving Size: 1 bowl (about 1½ cups soup with bread and cheese)
• Calories: Approx. 420
• Sugar: Approx. 10 g
• Sodium: Approx. 980 mg (will vary with broth)
• Fat: Approx. 22 g
• Saturated Fat: Approx. 12 g
• Unsaturated Fat: Approx. 9 g
• Trans Fat: 0 g (varies with butter used)
• Carbohydrates: Approx. 35 g
• Fiber: Approx. 3 g
• Protein: Approx. 18 g
• Cholesterol: Approx. 55 mg

Keywords: best French onion soup, classic French onion soup, caramelized onion soup, Gruyère onion soup, bistro onion soup