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French Onion Soup

This classic french onion soup  is made with caramelized onions simmered in beef broth, wine and brandy. Because of this, it has both intense savory flavor from the liquids as well as natural sweetness from the softened onions. 
Print Recipe
Prep Time 20 minutes
Cook Time 30 minutes
Caramelizing Onions Time 1 hour
Total Time 1 hour 50 minutes
Course Soup
Cuisine French
Servings 4

Ingredients
  

  • 4 pounds yellow onions (peeled and thinly sliced
  • 3 tablespoons butter
  • 4 cloves garlic (minced
  • 3 tablespoons flour
  • ½ cup dry white wine.
  • 6 cups beef stock or vegetable stock for a vegetarian version
  • 1 teaspoon Worcestershire sauce
  • 1 bay leaf
  • 3 sprigs fresh thyme or 1 teaspoon dried thyme
  • Fine sea salt and freshly-cracked black pepper
  • Baguette

Instructions
 

How to Caramelize Onions

  • Slice the Onions: Peel and thinly slice 4 pounds of yellow onions. Yellow onions offer a sweeter taste when caramelized and give the soup its signature rich flavor.
  • Melt Butter: In a large pot or Dutch oven, melt 3 tablespoons of butter over medium heat. Add the sliced onions and stir to coat them in the butter.
  • Cook the Onions Slowly: Let the onions cook on medium heat for about an hour. Stir occasionally to prevent burning, ensuring that they soften and develop a golden brown color. This slow cooking process enhances their natural sweetness.
  • Increase Heat for Browning: For the last 20 minutes, you can increase the heat to medium-high to deepen the caramelization and achieve a golden, rich color. Stir occasionally to avoid burning.

How to Make French Onion Soup

  • Build the Flavor: Once the onions are caramelized, add 3 tablespoons of flour to the softened onions and cook for about 2 minutes, stirring constantly. This helps to thicken the soup and build a smooth texture.
  • Deglaze with Wine: Pour in ½ cup of dry white wine, stirring to deglaze the pot and allow the wine to reduce. This step adds acidity and a complex depth of flavor to the soup.
  • Add the Stock and Seasoning: Add 6 cups of beef stock (or vegetable stock), 1 teaspoon Worcestershire sauce, 1 bay leaf, and 3 sprigs of thyme (or 1 teaspoon dried thyme). Stir to combine. Bring the soup to a simmer and let it cook for about 10 minutes to infuse the flavors.
  • Prepare the Baguette Croutons: While the soup simmers, slice the baguette into 1-inch slices. Place the slices on a baking sheet and toast them in the oven at 350°F (175°C) until lightly golden.
  • Assemble the Soup: Once the soup is done simmering, remove the bay leaf and thyme sprigs. Ladle the hot soup into oven-safe bowls and top each bowl with a toasted baguette slice.
  • Top with Cheese: Generously sprinkle grated cheese (typically Gruyère or Swiss) over the baguette slices. Place the bowls on a baking sheet and broil for 2-3 minutes until the cheese is melted, bubbly, and slightly browned.
  • Serve and Enjoy: Serve the French Onion Soup piping hot, garnished with extra fresh thyme or a sprinkle of black pepper, and enjoy the deep, rich flavors.

Notes

Caramelizing Onions: The key to a flavorful French Onion Soup is slow caramelization of the onions. Don't rush the process; let them cook gently to bring out their natural sweetness.
Use High-Quality Stock: For the richest flavor, opt for beef stock instead of broth. If you prefer a vegetarian version, vegetable stock works well.
Wine Choice: Dry white wine works best to deglaze and balance the richness of the soup. Avoid sweet wines.
Use Gruyère or Swiss Cheese: Gruyère is the classic choice for French Onion Soup, providing both flavor and meltability. You can also use Swiss cheese, but avoid low-fat cheese, as it won't melt as well.
Thickening the Soup: Adding flour to the caramelized onions helps thicken the broth. If you prefer a thinner soup, you can reduce the flour by half.
Keyword Caramelized Onion Soup, Classic Onion Soup, French Onion Soup, Rich Onion Soup