I made this cozy French Onion Chicken Soup—a delicious fusion of classic French onion soup and comforting chicken soup. It starts with deeply caramelized onions, then simmers with chicken, vegetables, and herbs, topped with cheesy Gruyère toasts. It’s rich, warming, and perfect for satisfying big cravings.

Why You’ll Love This Recipe

I love this soup because the sweet-savory caramelized onions build deep flavor over time. The tender chicken and veggies soak up that richness, and finishing with melty cheese on toast makes each bowl feel indulgent and complete. It's one of the most comforting soups I’ve made—I already cooked it twice in a week.

ingredients

(Here's a tip: Check out the full list of ingredients and measurements in the recipe card below.)

3 lb yellow onions (about 4 large or 6 medium)
6 tablespoon unsalted butter, divided
1 teaspoon dried thyme
2 dried bay leaves
2½ teaspoon kosher salt, divided
½ teaspoon freshly ground black pepper
3 medium carrots, sliced (about 1¼ cups)
3 celery stalks, sliced (about 1 cup)
3 garlic cloves, minced
2 lb boneless skinless chicken breasts or thighs
¾ cup dry white wine
1 tablespoon dry sherry
¼ cup all-purpose flour
6 cups low-sodium chicken broth
Optional for cheesy toasts:
- ½ baguette, sliced
- 2 oz Gruyère cheese (about heaping ½ cup)

directions

Peel, halve, and thinly slice the onions (about 10 cups).
In a large Dutch oven over medium heat, melt 4 tablespoons of butter. Add the onions, thyme, bay leaves, 1½ teaspoons salt, and pepper. Stir often, scraping the pot, until the onions are soft and deeply golden brown, about 35–45 minutes.
While the onions cook, slice the carrots and celery, and mince the garlic.
Add the remaining 2 tablespoons of butter to the pot, then add the carrots, celery, and garlic. Cook for about 5 minutes until the vegetables are slightly tender.
Season the chicken with 1 teaspoon salt. If the chicken breasts are thick, I like to butterfly them so they cook more evenly.
Pour in the white wine and sherry. Let it cook for 2–3 minutes until most of the liquid evaporates. Stir in the flour and cook for 1 minute.
Slowly pour in the chicken broth while stirring. Lay the chicken pieces in the pot in a single layer. Increase the heat to medium-high and bring to a lively simmer.
Reduce the heat to maintain a gentle simmer and cook, stirring occasionally, until the chicken is cooked through. Thighs usually take about 10 minutes; breasts may take 12–20 minutes depending on thickness.
While the chicken simmers, make the cheesy toasts. Preheat the broiler. Place baguette slices on a baking sheet, top with shredded Gruyère, and broil for 30 seconds to 1 minute until the cheese is melted and bubbling.
Transfer the cooked chicken to a cutting board. Shred it with two forks and return it to the pot. Discard the bay leaves, taste, and adjust the seasoning if needed.
Ladle the soup into bowls and top each with a cheesy toast.

Servings and timing

Servings: About 8
Prep time: 15 minutes
Cook time: 1 hour 10 minutes
Total time: 1 hour 25 minutes

Variations

I like using chicken thighs for extra flavor, but chicken breasts work great if I want a leaner soup.
For deeper richness, I sometimes swap chicken broth with beef broth.
I’ve replaced white wine with more sherry or even a splash of apple cider vinegar in a pinch.
I love switching up the cheese—Fontina, Swiss, or Parmesan are all delicious on the toast.
For a low-carb version, I simply skip the bread or use roasted cauliflower slices instead.

storage/reheating

I store leftovers in the fridge for up to 4 days in an airtight container. I reheat it gently on the stove over medium-low heat so the flavors stay intact. When freezing, I portion the soup into freezer-safe containers and freeze for up to 3 months. I thaw it overnight in the fridge and always make the cheesy toasts fresh when serving.

FAQs

How can I make this gluten-free?

I swap the flour for a cornstarch slurry (1 tablespoon cornstarch mixed with 1 tablespoon water) and stir it in at the end to thicken the soup.

Can I use chicken thighs instead of breasts?

Yes, I often do that. Thighs stay more tender and juicy, and they add a rich flavor that I really enjoy.

What can I use instead of white wine?

When I don’t have wine, I use extra chicken broth with a splash of vinegar or lemon juice to mimic the acidity.

Do I have to make the cheesy toasts?

Not at all. I love the crunch and richness they add, but the soup is still hearty and flavorful on its own.

Can I make this ahead of time?

Absolutely. I often make it a day in advance—the flavors deepen overnight. I just wait to add the cheesy toasts until serving.

Conclusion

This French Onion Chicken Soup is comfort in a bowl. The caramelized onions build incredible depth, the chicken makes it hearty, and the cheesy toast on top gives it that special touch. It’s a recipe I keep coming back to when I want something that feels classic but extra satisfying.