Classic French Onion Soup (Printable Version)

Deeply caramelized onions in savory broth, topped with toasted bread and golden Gruyère cheese.

# 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

# How to Make It:

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

# Expert Advice:

01 -
  • The caramelized onions taste nothing like raw onions—they become sweet, complex, and almost jammy in a way that surprises first-time makers.
  • It's the kind of soup that feels fancy enough for guests but simple enough to make on a quiet weeknight when you need comfort.
  • One bowl fills you up completely, making it perfect for lunch or a light dinner paired with crusty bread and wine.
02 -
  • Don't skip or rush the caramelization step no matter how tempting it is—low heat and patience are what transform plain onions into something transcendent, not a hotter flame.
  • The soup actually tastes even better the next day after flavors have had time to settle and deepen, so don't hesitate to make it ahead and rehale it gently before adding the cheese topping.
03 -
  • If you have access to a combination of beef, chicken, and vegetable stocks, mixing them creates a more nuanced flavor than using just one—each adds its own character to the final broth.
  • Gruyère is traditional for good reason, but Emmental works beautifully if that's what you have, and aged Comté adds an almost sweet nuttiness that's equally impressive.
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