Classic French Onion Soup (Printer-friendly)

Rich, comforting French classic with caramelized onions in savory broth, topped with toasted bread and golden Gruyère.

# What You'll Need:

→ Onions

01 - 3 large yellow onions, thinly sliced
02 - 1 tablespoon unsalted butter
03 - 1 tablespoon olive oil

→ Soup Base

04 - 2 cloves garlic, minced
05 - 1 teaspoon sugar
06 - 1/2 teaspoon salt
07 - 1/4 teaspoon freshly ground black pepper
08 - 2 tablespoons all-purpose flour
09 - 1/2 cup dry white wine
10 - 5 cups beef or vegetable stock
11 - 2 sprigs fresh thyme
12 - 1 bay leaf

→ Topping

13 - 4 slices French baguette, about 1 inch thick
14 - 1 tablespoon olive oil for bread
15 - 1 cup Gruyère cheese, grated

# Steps:

01 - Heat butter and olive oil in a large pot over medium heat. Add sliced onions and stir to coat. Cook, stirring frequently, for 35-40 minutes until onions are soft and deeply caramelized. Add sugar and salt halfway through cooking to enhance caramelization.
02 - Add minced garlic to the caramelized onions and cook for 1 minute until fragrant.
03 - Sprinkle flour over the mixture and stir constantly for 2 minutes to slightly thicken the base.
04 - Pour in white wine and scrape the bottom of the pot with a spoon to release all caramelized bits.
05 - Pour in the stock and add thyme sprigs and bay leaf. Bring to a simmer, then reduce heat. Cook uncovered for 20-25 minutes. Remove thyme and bay leaf. Season with pepper and additional salt to taste.
06 - Preheat the oven broiler. Place baguette slices on a baking sheet, brush both sides with olive oil, and toast under the broiler for 1-2 minutes per side until golden.
07 - Ladle hot soup into oven-safe bowls. Top each bowl with a toasted baguette slice and cover generously with grated Gruyère cheese.
08 - Place bowls on a baking sheet and broil for 2-3 minutes until cheese is melted, bubbly, and golden brown. Serve immediately.

# Expert Advice:

01 -
  • The contrast between the deeply savory broth and the gooey, crusty cheese topping creates a texture experience that store-bought versions can never match.
  • Despite its elegant restaurant reputation, making this at home lets you control the sweetness of the onions and the richness of the broth exactly to your preference.
02 -
  • The color of your onions determines the flavor of your soup – stop too early and you miss the deep complexity that only proper caramelization brings.
  • Oven-safe soup bowls are non-negotiable for authentic French onion soup, as the final broiling step is what creates that iconic cheese crust that makes everyone fight for the first spoonful.
03 -
  • For deeper flavor development, add a tablespoon of balsamic vinegar to the onions during the last five minutes of caramelization.
  • Float the toasted bread on the soup for just 30 seconds before adding cheese – this prevents the bread from becoming too soggy while still allowing it to absorb some of the broth.
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