Before you cook
Background Recipe story & origin
French onion soup dates to ancient Rome, where onions were cheap and abundant. The modern version emerged in 18th-century France, with the gratinéed topping appearing in Parisian restaurants. Legend credits the overnight market workers at Les Halles, Paris's central food market, with popularizing the dish as a late-night restorative. The key is deeply caramelized onions - cooked 45-60 minutes until dark brown and sweet - deglazed with white wine or cognac, then simmered in rich beef stock. The gratin topping - crusty bread covered in melted Gruyère - was added later, creating the dish's signature cheese pull. Julia Child's version popularized it in America. Traditional preparation uses a mix of onion varieties. The soup became a symbol of Parisian bistro cooking, served in individual oven-safe crocks with the cheese broiled until bubbling and golden.
Before you start Equipment you'll need
- Dutch oven — Provides even heat distribution for caramelizing onions and building French onion soup properly
- oven-safe crocks — Individual ceramic crocks provide proper shape and even heat for gratinéeing soup with cheese topping
Safety Safety & allergen notes
- Use caution with hot surfaces and oils.
- Handle knives carefully when prepping ingredients.
Non-negotiables Rules for success
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Caramelize the onions
Cook onions in butter and oil over medium-low heat (275-300°F surface), stirring occasionally, until...
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Build the soup
Sprinkle flour over onions, stir 2 minutes. Add wine, scrape up fond. Add broth, thyme, bay leaf. Si...
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Gratinée under broiler
Ladle soup into oven-safe crocks. Top with toasted baguette slices. Cover generously with Gruyère. B...
Prep Get set first
About 10 min of prep
- Prepare Dutch oven
- Prepare oven-safe crocks
This recipe takes about 90 minutes total.
Ingredients
Instructions
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Caramelize the onions
Cook onions in butter and oil over medium-low heat (275-300°F surface), stirring occasionally, until deeply golden brown, 45-60 minutes. Add sugar halfway through to help caramelization.
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Build the soup
Sprinkle flour over onions, stir 2 minutes. Add wine, scrape up fond. Add broth, thyme, bay leaf. Simmer 20 minutes. Add cognac. Season.
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Gratinée under broiler
Ladle soup into oven-safe crocks. Top with toasted baguette slices. Cover generously with Gruyère. Broil until cheese is bubbling and browned, 3-5 minutes.