French Onion Soup
AI-generated image
French

French Onion Soup

Slow-caramelized onions, aromatic thyme, and rich beef broth are finished with toasted baguette and bubbling Gruyère for a classic French gratinée soup.

90 min 4 servings Medium
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How to prepare

1
Melt 30 g of the butter with the olive oil in a heavy 4-liter pot over medium heat. Add the sliced onions, thyme, salt, and pepper, then toss until every onion is glossy. Cook for 10 minutes, stirring occasionally, until softened.
2
Reduce the heat to medium-low and cook the onions for 35–40 minutes, stirring every few minutes, until deeply golden, jammy, and reduced to roughly one-quarter of their original volume.
Deeply caramelized onions in a heavy pot AI-generated image
3
Stir in the grated garlic and cook for 1 minute, until fragrant. Pour in the wine and scrape the browned fond from the base of the pot. Simmer for 3–4 minutes, until the wine is reduced by about half.
4
Add the hot beef broth and Worcestershire sauce. Bring to a gentle boil, then lower the heat and simmer uncovered for 20 minutes so the flavors meld. Remove the thyme sprigs and adjust the seasoning.
5
Heat the oven to 220°C. Melt the remaining 15 g butter and brush it over the baguette slices. Arrange the slices on a baking sheet and bake for 6–8 minutes, turning once, until crisp and lightly browned.
6
Divide the hot soup among 4 ovenproof bowls set on a baking sheet. Place all 8 toasted baguette slices across the bowls, 2 slices per bowl, and cover evenly with the grated Gruyère.
7
Bake for 8–10 minutes, then switch to the broiler for 1–2 minutes until the cheese is fully melted, bubbling, and browned in spots. Rest for 3 minutes before serving; the bowls and soup will be very hot.
French onion soup with bubbling browned Gruyère AI-generated image

Why this recipe works

Low, patient cooking turns ordinary onions sweet and deeply savory, while crisp bread and melted Gruyère provide the contrasting texture and richness that define the gratinée finish.

Storage and reheating

How to store it

Refrigerate the soup without the bread and cheese for up to 4 days in a covered container. Toasted bread is best stored separately.

How to reheat it

Reheat the soup gently in a saucepan until steaming throughout, then top with fresh toast and cheese and broil until melted and browned.

Nutrition / serving

461kcal
16.34 gprotein
41.46 gcarbs
23.78 gfat
P
Pantryvale editorial kitchen
Recipe prepared for publication with complete ingredients and ordered cooking steps.
Published 15 Aug 2026 · updated 15 Aug 2026