Classic French Onion Soup (Printable)

Savory French bistro soup with caramelized onions, beef broth, and melted Gruyère on toasted baguette.

# What You'll Need:

→ Alliums

01 - 4 large yellow onions, thinly sliced
02 - 2 large leeks, white and light green parts only, cleaned and thinly sliced
03 - 3 shallots, thinly sliced
04 - 3 garlic cloves, minced

→ Fats

05 - 3 tablespoons unsalted butter
06 - 2 tablespoons olive oil

→ Broth & Umami

07 - 8 cups high-quality beef broth
08 - 1 tablespoon Worcestershire sauce
09 - 2 teaspoons soy sauce
10 - 1/2 cup dry white wine
11 - 2 teaspoons fresh thyme leaves
12 - 1 bay leaf

→ Bread & Cheese

13 - 1 baguette, sliced into 1/2-inch rounds
14 - 2 cups Gruyère cheese, grated
15 - 1/2 cup Parmesan cheese, grated

→ Seasonings

16 - Salt and freshly ground black pepper, to taste

# How-To Steps:

01 - In a large heavy-bottomed pot or Dutch oven, heat the butter and olive oil over medium heat until the butter is fully melted and the mixture is shimmering.
02 - Add the sliced onions, leeks, and shallots. Sauté, stirring frequently, until very soft and deep golden brown, approximately 35 to 40 minutes. Add the minced garlic and cook for 2 minutes more.
03 - Pour in the dry white wine and scrape up any browned bits from the bottom of the pot using a wooden spoon.
04 - Stir in the beef broth, Worcestershire sauce, soy sauce, thyme, and bay leaf. Bring to a simmer, then reduce heat and cook uncovered for 30 minutes, stirring occasionally.
05 - Season the soup with salt and pepper to taste. Remove and discard the bay leaf.
06 - Preheat the oven broiler. Arrange baguette slices on a baking sheet and toast under the broiler until golden, approximately 1 to 2 minutes per side.
07 - Ladle the hot soup into oven-safe bowls. Top each bowl with toasted baguette slices and a generous amount of Gruyère cheese and Parmesan cheese.
08 - Place bowls under the broiler until the cheese is melted and bubbly, approximately 3 to 5 minutes.
09 - Transfer bowls carefully to serving plates and serve immediately. Garnish with extra fresh thyme if desired.

# Expert Tips:

01 -
  • The slow caramelization creates a depth of flavor you simply cannot rush, turning humble onions into liquid gold.
  • It feels fancy enough for guests but forgiving enough that you can make it on a weeknight while catching up on podcasts.
  • That moment when the cheese bubbles under the broiler and you crack through the crust with your spoon is pure magic.
02 -
  • Do not turn up the heat to rush the caramelization, high heat will scorch the onions and leave a bitter taste instead of the sweet, rich flavor you're after.
  • Make sure your soup bowls are truly oven safe before putting them under the broiler, I learned this the hard way with a cracked bowl and a smoky kitchen.
03 -
  • Use a mix of alliums instead of just onions, the leeks and shallots add layers of flavor that make the soup taste more complex and interesting.
  • Always taste your broth before adding it, if it's bland, your soup will be too, so start with the best you can afford or make your own if you have time.
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