Make a protein-rich dinner with the French Onion Chicken casserole, a delicious twist on your favorite soup. This dish is crafted with broth, caramelized onions, butter, chicken, and cheese, elevating the classic soup to a whole new level!

Pair it with Boursin Mashed Potatoes or Air Fryer Asparagus and Sauteed Green Beans with Garlic for a full meal that your family is sure to love!

French Onion Soup Chicken
Most of us have enjoyed the comfort of a hot bowl of French Onion Soup, known for its thick bread and perfectly broiled cheese topping. But did you know that you can use those same flavors and ingredients to make a delicious sauce for chicken? Today, we'll show you how to make French Onion Chicken, a protein-rich meal that's just as comforting as the soup version! The chicken is topped with a rich French onion-style sauce. The ingredients are similar - onions, broth, and cheese - but we'll also add chicken breasts and a variety of seasonings to elevate the recipe.

You'll Need
- Chicken Breasts: Boneless, skinless chicken breasts are ideal for this French onion chicken recipe. You can also use chicken thighs if you prefer darker meat.
- Salt and Pepper: Adjust to your taste.
- Italian Seasoning and Herbes de Provence: These herb blends add a complex flavor. If you don't have Herbes de Provence, use more Italian seasoning or a mix of dried thyme, rosemary, and oregano.
- Garlic Powder: This adds a nice garlic flavor without the burn of fresh garlic.
- Flour: Used for dredging the chicken, giving it a nice crust. You can use gluten-free flour or cornstarch as a substitute if needed.
- Parmesan Cheese: Adds a nice, salty flavor to the chicken coating. Grated Parmesan works best, but you can also use other hard, aged cheeses like Pecorino Romano.
- Olive Oil and Unsalted Butter: These are used for frying the chicken and cooking the onions.
- White Onions: The key ingredient for the French onion flavor. Yellow onions can be used as a substitute but avoid sweeter onions like Vidalia as they might change the flavor profile.
- Worcestershire Sauce and Balsamic Vinegar: They add depth and a bit of acidity to the sauce. If you don’t have it, soy sauce will work too. Apple cider vinegar can replace balsamic vinegar.
- Dry White Wine or Chicken Stock : The wine adds a nice depth of flavor, but if you prefer not to use alcohol, chicken or vegetable stock is a fine substitute.
- Beef Broth and Chicken Broth: Both broths are used for the sauce base. Use vegetable broth for a lighter flavor.
- Beef Bouillon: Enhances the meaty flavor of the sauce.
- Mozzarella Cheese, Provolone, or Gruyere Cheese: These cheeses melt well and complement the dish. You can choose one or a combination. For a different taste, try Swiss cheese or cheddar.
- Fresh Thyme: Adds a fresh aroma.

How to Make French Onion Chicken Casserole
Slice each chicken breast into 2 thinner pieces. Place them between sheets of plastic wrap and pound to ¼ inch thickness.

Season the chicken and coat it in a flour and Parmesan mix.

Sear the chicken fillets, cooking each side for about 3 minutes until golden brown. Then, set the chicken aside.

In the same skillet, heat olive oil and butter. Use a silicone spatula to scrape and "clean" the fond (browned bits) from the bottom of the pot, which will enhance the sauce's flavor. Then, add the sliced onions.

Let the onions soften for around 5 minutes. After that, add Worcestershire sauce, balsamic vinegar, Herbes de Provence, sage, and bay leaves to the mixture.
Cover the skillet and reduce the heat to a gentle simmer. Allow the mixture to cook for 30 minutes, stirring occasionally for even cooking. Then, remove the cover and increase the heat to medium, continuing to cook for an additional 5-10 minutes. Add the wine (or chicken stock) and garlic.

Continue cooking uncovered until it has nearly evaporated, about 5-10 minutes. Then add flour and stir to coat the onions. Cook for 1-2 minutes to get rid of the raw flour taste.
Pour in the chicken broth, beef broth, and add the beef bouillon. Bring the mixture to a gentle boil and allow it to reduce and thicken, which should take about 3-5 minutes. Then, remove it from the heat.

Place the chicken together with the juices back into the skillet. Sprinkle cheese over the chicken. Bake at 475°F for 10-15 minutes, until the cheese starts to brown and bubble. Once done, remove it from the heat.

Garnish with thyme and serve alongside mashed potatoes.
Storage
Keep it in an airtight container and refrigerate it for up to 3 days. Alternatively, you can freeze it for up to 3 months.

How to Reheat French Onion Soup Chicken
Oven Method (Recommended):
- Preheat your oven to 350°F (175°C).
- Place the French Onion Chicken in an oven-safe dish. If the dish seems dry, add a splash of chicken broth or water to keep the chicken moist.
- Cover the dish with aluminum foil to prevent the chicken from drying out.
- Heat for 15-20 minutes, or until the chicken is heated through. If the chicken has cheese on top, you can remove the foil in the last few minutes of heating to allow the cheese to re-melt and become bubbly.
Microwave Method:
- Place the chicken in a microwave-safe dish.
- Heat on medium power in 1-minute intervals, checking for warmth and stirring if necessary to heat evenly.
Stovetop Method:
- Heat a skillet over medium heat and add the chicken.
- If the chicken is dry, add a bit of chicken broth or water.
- Cover the skillet and heat for a few minutes, stirring occasionally until the chicken is warmed through.

You’ll Need to Try These!
Air Fryer Parmesan Crusted Chicken with Mayo


If you make this recipe be sure to leave a comment or give this recipe a rating ⭐⭐⭐⭐⭐! I will be happy to hear from you!
French Onion Chicken
Ingredients
Chicken
- 3 medium boneless skinless chicken breasts, halved horizontally to make 6 fillets
- Salt and pepper to taste
- 2 teaspoons Italian seasoning
- 2 teaspoons Herbes de Provence
- ½ tablespoon garlic powder
- ½ cup all-purpose flour
- ¼ cup Parmesan cheese shredded
- 3 tablespoons olive oil
- 1 tablespoon unsalted butter
Sauce
- 2 tablespoons unsalted butter
- 1 tablespoon olive oil
- 4 large white onions equal to 1.5 pounds
- 2 teaspoons Worcestershire Sauce
- 2 teaspoons balsamic vinegar
- 2 teaspoons Herbes de Provence
- ¼ teaspoon dried sage
- 2 bay leaves
- 3 cloves garlic minced
- ½ cup dry white wine like chardonnay or pinot grigio (or chicken stock)
- 2 tablespoons flour
- 1 cup beef broth
- 1 cup chicken broth
- 1 beef bouillon cube crushed
- 1 ¾ cups mozzarella cheese provolone or gruyere cheese
- Fresh thyme to garnish
Instructions
Prepare the Chicken
- Start by slicing the CHICKEN into 2 thinner pieces horizontally to make 6 fillets. Then, sandwich the fillets between sheets of plastic wrap. Using a meat tenderizer, gently pound the chicken until it's about ¼ inch in thickness. (*Helpful Hint: Using the textured side of the tenderizer can speed up this process.)
- Pat the chicken dry to remove any excess moisture. Then season each side evenly with SALT, PEPPER, ITALIAN SEASONING, HERBES DE PROVENCE, and GARLIC POWDER for flavor.
- In a separate bowl, mix together the FLOUR and PARMESAN cheese. Dredge each piece of chicken in this flour and cheese mixture, ensuring it's well-coated.
- Heat 3 tablespoons of OIL and 1 tablespoon of BUTTER in a pan over medium-high heat. Cook the chicken for approximately 3 minutes on each side until it develops a nice golden crust. Be sure to adjust the heat as necessary during the searing process. If the pan gets too hot, turn the heat down slightly, and then increase it again if needed. Add a bit more olive oil if or as required.
- Once the chicken is seared, remove it from the pan and set it aside. Cover it loosely with aluminum foil to keep it warm. If the chicken isn't completely cooked through at this point, don't worry – it will finish cooking when you bake it in the oven.
Caramelize the Onions
- Melt 2 tablespoons of BUTTER and 1 tablespoon of OLIVE OIL over medium heat. Then, use a silicone spatula to scrape off the chicken remnants (known as "fond") from the bottom of the skillet. Doing this will incorporate more flavor into your sauce.
- Add the sliced ONIONS to the skillet and stir to ensure they are well coated with the butter and olive oil mixture. Allow the onions to soften for about 5 minutes. Then, add WORCESTERSHIRE SAUCE, BALSAMIC VINEGAR, HERBES DE PROVENCE, SAGE and BAY LEAVES to the mix.
- Cover the skillet and lower the heat to a gentle simmer. Let the mixture cook for 30 minutes, stirring it occasionally to ensure even cooking.
- Remove the cover and raise the heat to medium. Continue cooking for an additional 5-10 minutes.
Make the Sauce
- Set your oven to preheat at 475 degrees Fahrenheit.
- Add the GARLIC and WHITE WINE (or chicken stock) into the skillet. Continue cooking without a cover until the liquid has nearly fully reduced, about 10 minutes.
- Sprinkle the FLOUR over the mixture in the skillet and stir well to coat everything evenly. Cook for 1-2 minutes, or until the raw smell of the flour dissipates.
- Pour in the CHICKEN BROTH, BEEF BROTH, and BEEF BOUILLON into the skillet. Turn up the heat to medium-high and bring the sauce to a gentle boil. Allow it to simmer for 3-5 minutes, or until it thickens and reduces slightly. Then, remove the skillet from the heat.
Bake
- If your skillet is not oven-safe, transfer the sauce to a large oven-safe casserole dish before baking.
- Place the chicken back into the skillet and evenly distribute CHEESE on top. Then, bake it in the oven preheated to 475 degrees Fahrenheit for 10-15 minutes, until you see the cheese turning golden brown and starting to bubble.
- After removing the dish from the oven, garnish with FRESH THYME.
- Serve and enjoy!
Video
Notes
Nutrition
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Bob Hunt says
OMG! Made exactly except minus 1 onion and 1 chicken breast since there is only two of us. Will definitely be making this again.
chefjar says
Hi Bob! That's wonderful to hear! I'm glad you enjoyed it and tailored the recipe perfectly for two. And thanks for sharing your experience!