Best French Onion Soup

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I learned to love French onion soup the hard way — standing by the stove, stirring slowly as the kitchen filled with that sweet, nutty aroma of deeply caramelized onions. This version is simple and reliable: four large onions cooked low and slow, a splash of dry white wine, rich beef broth, and a browned Gruyère crust on top. It’s the kind of recipe you make when you want comfort that feels a little special — perfect for chilly nights, a cozy dinner for two, or an impressive starter for friends. If you want a quicker take on a classic, I’ve also tested a faster method that keeps the flavor intact and you can compare it with this recipe for timing and technique here.

What makes this recipe special

This French onion soup delivers deep, layered flavor without fuss. The long caramelization of the onions is the foundation — sugar and salt coax out moisture and then encourage browning. A splash of dry white wine brightens the rich beef stock, while thyme and bay leaf add an earthy, aromatic backbone. Topped with toasted baguette and a bubbling layer of Gruyère, the contrast of silky broth, tender onions, crunchy bread, and gooey cheese is what people crave.

“A bowl of this feels like a warm blanket: deeply savory, slightly sweet, and gloriously cheesy.”

This recipe is ideal for weeknight comfort, dinner parties where you want something low-maintenance but memorable, and holiday menus where you need a classic crowd-pleaser. For other takes on traditional approaches, I also compare variations in a classic format that’s useful when you want to tweak texture or richness here.

The cooking process explained

Before you start, expect about 1 hour total active time (most of that is hands-off caramelizing and simmering) and about 30–40 minutes of attentive onion browning. The basic flow:

• Slice onions thinly.
• Sweat and slowly caramelize them in butter + olive oil with a pinch of salt and sugar.
• Deglaze with dry white wine.
• Add beef broth, thyme, and bay leaf; simmer to meld flavors.
• Ladle into oven-safe bowls, top with baguette slices and Gruyère.
• Broil briefly until the cheese bubbles and browns.

This order ensures the onions develop deep flavor first, then the liquid components finish the soup without overcooking the texture.

Gather these items

• 4 large onions, thinly sliced (yellow or sweet onions work best)
• 4 tablespoons unsalted butter
• 1 tablespoon olive oil
• 1 teaspoon salt
• 1 teaspoon sugar (helps caramelization)
• 4 cups beef broth (use low-sodium if you want control over salt)
• 1 cup dry white wine (Sauvignon Blanc or Pinot Grigio are good)
• 1 teaspoon dried thyme (or 1 tablespoon fresh)
• 1 bay leaf
• Freshly ground black pepper to taste
• 1 baguette, sliced into rounds
• 2 cups grated Gruyère cheese

Substitution notes: For a lighter version, swap half the beef broth for chicken stock or use vegetable broth for a vegetarian-friendly base (add a splash of soy sauce or miso for depth). If you can’t find Gruyère, Swiss or a mix of Emmental and Parmesan will work.

For more ingredient-minded variations and pantry swaps, see another classic guide I tested that breaks down substitutions and technique here.

Step-by-step instructions

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1. Heat a large pot over medium heat. Add the butter and olive oil until the butter melts.
2. Add the thinly sliced onions, then sprinkle in the salt and sugar. Stir to coat.
3. Cook the onions, stirring frequently so they brown evenly. This takes 30–40 minutes. Be patient — you want a deep golden to mahogany color, not burned bits.
4. Pour in the dry white wine to deglaze the pot. Scrape any browned bits from the bottom with a wooden spoon.
5. Add the beef broth, thyme, bay leaf, and a few grinds of black pepper. Bring to a simmer.
6. Let the soup simmer gently for about 30 minutes to meld the flavors. Remove the bay leaf and taste for seasoning.
7. Preheat your oven’s broiler. Ladle the hot soup into oven-safe bowls. Top each bowl with baguette slices, then pile grated Gruyère on top.
8. Place the bowls under the broiler until the cheese is bubbly and golden brown, about 3–5 minutes. Watch closely to avoid burning.
9. Remove carefully (bowls will be hot). Let sit 1–2 minutes, then serve.

Best ways to enjoy it

Serve the soup in warm bowls so it stays hot longer. Pair it with:

• A simple green salad dressed in lemon vinaigrette to cut the richness.
• A crisp white wine (the same style used for cooking) or a light-bodied red like Pinot Noir.
• For a heartier meal, add a roasted chicken or a charcuterie board alongside.

For an elevated presentation, place a thin baguette round under the cheese so it crisps into a golden platform, and sprinkle a little finely grated Parmesan on top right after broiling for an extra savory finish. If you’d like plating inspiration for entertaining, see an elevated variation I developed with show-stopping finishes here.

Storage and reheating tips

• Refrigerator: Store leftover soup (without bread and cheese) in an airtight container for up to 3–4 days.
• Freezer: Freeze cooled soup in freezer-safe containers for up to 3 months. Thaw overnight in the fridge before reheating.
• Reheating: Gently reheat on the stovetop over medium-low heat until simmering. If you want to reconstitute the broiled cheese topping, ladle heated soup into oven-safe bowls, add baguette and cheese, and broil until bubbly.
• Food safety: Cool soup to room temperature for no more than 2 hours before refrigerating; reheat to at least 165°F (74°C) before serving.

Pro chef tips

• Don’t rush the onions. Proper caramelization is the flavor base — lower heat and patience beat high heat every time.
• Use a heavy-bottomed pot to distribute heat evenly and prevent hot spots.
• When the onions near deep golden color, reduce the heat slightly and stir more often to avoid burning. Burnt onions will taste bitter.
• If you prefer a clearer broth, skim any fat or scum after simmering.
• Toast the baguette lightly before topping so it doesn’t turn gummy under the cheese.

Creative twists

• Mushroom & thyme: Add sliced cremini mushrooms when onions are nearly done for extra umami.
• Sherry or cognac: Substitute half the wine with a splash of sherry for a sweeter, nuttier note.
• Vegetarian version: Use vegetable broth plus a tablespoon of soy sauce or mushroom bouillon for depth; swap Gruyère for a melting vegetarian cheese.
• Herbed crust: Mix grated Parmesan into the Gruyère for a saltier, crispier top.

Your questions answered

Q: How long does this whole recipe take?
A: Plan for about 1 hour 15 minutes total. Caramelizing onions 30–40 minutes, then a 30-minute simmer and a few minutes under the broiler.

Q: Can I make this ahead for guests?
A: Yes. Prepare the soup through the simmering step, cool, and refrigerate up to 3 days. Reheat and finish under the broiler with bread and cheese just before serving.

Q: Is beef broth required?
A: Beef broth gives the traditional deep flavor, but you can use mushroom or vegetable broth and add a splash of soy sauce or miso for savory depth if you want a vegetarian base.

Q: How do I avoid a soggy baguette?
A: Toast the baguette slices before topping, or place them under the broiler only long enough to warm and crisp the bottom while the cheese melts.

Conclusion

For additional perspectives and recipe variations from trusted cooks, try this homemade version on Belly Full for a classic approach French Onion Soup: The Best Homemade Version Around!, Andrew Zimmern’s detailed take for technique notes The Best French Onion Soup – Andrew Zimmern, Serious Eats’ tested recipe that dives into science and timing French Onion Soup (Soupe à l’Oignon Gratinée), and a reliable classic from Gimme Some Oven with clear steps and photos French Onion Soup.