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A bowl of French Onion Chicken Soup topped with toasted baguette, bubbly melted Gruyère cheese, caramelized onions, and tender shredded chicken, garnished with fresh thyme.
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French Onion Chicken Soup

Rich, savory, and packed with sweet caramelized onions, tender chicken, and a bubbling Gruyère cheese topping, this French Onion Chicken Soup is the ultimate comfort food. Made with a blend of chicken and beef broth for incredible depth of flavor, it's a cozy meal that's perfect for chilly evenings.
Course Main Course, Soup
Cuisine French-American
Keyword Caramelized Onion Chicken Soup, Chicken French Onion Soup, comfort food soup, Cozy Chicken Soup, Easy French Onion Soup, French Onion Chicken Soup, French Onion Soup with Chicken, Gruyère Chicken Soup, Homemade French Onion Soup, rotisserie chicken soup
Prep Time 20 minutes
Cook Time 1 hour 20 minutes
Total Time 1 hour 40 minutes
Servings 6 servings
Calories 470kcal
Cost $24 for entire recipe

Equipment

  • Large Dutch oven or heavy-bottomed soup pot
  • Chef’s knife
  • Cutting board
  • wooden spoon
  • Measuring cups and measuring spoons
  • box grater
  • Baking sheet
  • Oven-safe soup bowls
  • Ladle
  • Tongs or spatula for handling toasted bread
  • Broiler or oven

Ingredients

Soup

  • 4 tablespoons unsalted butter
  • 1 tablespoon olive oil
  • 5 large yellow onions about 3 pounds, sliced ⅛ to ¼ inch thick
  • 1½ teaspoons kosher salt
  • 5 medium garlic cloves minced
  • 1 tablespoon all-purpose flour
  • ¼ cup dry white wine
  • 5 cups low-sodium chicken broth
  • 2 cups low-sodium beef broth
  • 1 tablespoon Worcestershire sauce
  • 2 teaspoons fresh thyme leaves or ¾ teaspoon dried thyme
  • 1 bay leaf
  • ½ teaspoon freshly ground black pepper
  • 2½ cups cooked chicken shredded or cut into bite-sized pieces
  • ½ to 1 teaspoon sherry vinegar or balsamic vinegar, to taste

Topping

  • 6 slices French baguette about ¾ inch thick
  • 2 cups freshly shredded Gruyère cheese
  • 2 tablespoons finely grated Parmesan cheese
  • Fresh thyme leaves or chopped chives for garnish (optional)

Instructions

  • Melt the butter and olive oil in a large Dutch oven over medium-low heat.
  • Add the sliced onions and kosher salt. Cook for 45 to 60 minutes, stirring every 3 to 5 minutes, until the onions are a deep mahogany brown with a soft, jam-like consistency. If they begin sticking before they're fully caramelized, add 1 to 2 tablespoons of water and scrape up the browned bits.
  • Stir in the minced garlic and cook for 1 minute, until fragrant.
  • Sprinkle the flour evenly over the onions and cook for 60 to 90 seconds, stirring constantly until no dry flour remains.
  • Pour in the white wine and scrape the bottom of the pot to loosen all the browned bits. Simmer until the wine has almost completely evaporated.
  • Stir in the chicken broth, beef broth, Worcestershire sauce, thyme, bay leaf, and black pepper. Bring to a gentle boil, then immediately reduce the heat to low and simmer uncovered for 25 minutes.
  • Stir in the cooked chicken and simmer for 5 minutes, just until heated through.
  • Remove the bay leaf. Remove the pot from the heat and stir in ½ teaspoon of sherry vinegar. Taste and add up to another ½ teaspoon if desired. Adjust the seasoning with additional salt and freshly ground black pepper if needed.
  • While the soup simmers, toast the baguette slices until crisp and lightly golden on both sides.
  • Position an oven rack about 6 inches below the broiler and preheat the broiler.
  • Place six oven-safe soup bowls on a rimmed baking sheet. Ladle the hot soup into the bowls, top each with a toasted baguette slice, and generously cover with the Gruyère and Parmesan cheeses.
  • Broil for 2 to 4 minutes, watching carefully, until the cheese is melted, bubbling, and deeply golden brown in spots.
  • Let the soup rest for 2 to 3 minutes before serving. Garnish with fresh thyme leaves or chopped chives, if desired.

Notes

This French Onion Chicken Soup combines the rich, savory flavors of classic French onion soup with tender chicken for a comforting meal that's perfect for lunch or dinner. These tips will help you achieve the best flavor and texture every time.

Caramelize the Onions Slowly

The onions are the foundation of this soup. Cook them over medium-low heat for 45 to 60 minutes until they become deep golden brown and soft with a jam-like consistency. Taking your time during this step develops the sweet, rich flavor that makes French onion soup so special.

Use Low-Sodium Broth

Using low-sodium chicken and beef broth gives you better control over the seasoning. Gruyère cheese, Parmesan, and Worcestershire sauce all contribute salt, so it's best to adjust the seasoning at the very end.

Freshly Shred the Cheese

Freshly shredded Gruyère melts more smoothly than pre-shredded cheese and creates the classic bubbly, golden topping. A small amount of Parmesan adds extra savory flavor without overpowering the Gruyère.

Add the Chicken at the End

Stir the cooked chicken into the soup during the final 5 minutes of cooking. This keeps the chicken moist and tender while allowing it to absorb the flavors of the broth.

Finish with Sherry Vinegar

A small splash of sherry vinegar added after removing the soup from the heat brightens the rich broth and balances the sweetness of the caramelized onions. If you don't have sherry vinegar, balsamic vinegar is a good substitute.

Toast the Bread Well

Toast the baguette slices until they are crisp and lightly golden before placing them on the soup. Well-toasted bread holds up better under the melted cheese and provides the perfect texture.

Watch the Broiler Carefully

Cheese can brown very quickly under the broiler. Keep a close eye on the soup and remove it as soon as the Gruyère is melted, bubbly, and golden brown.

Great for Meal Prep

The soup base can be made up to 3 days in advance and often tastes even better after the flavors have had time to develop. Store the soup separately from the bread and cheese, then assemble and broil each serving just before serving for the best results.