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All of the flavors that you love from a classic bowl of French onion soup are transformed into a hearty casserole! This easy French onion chicken bake includes tender chicken, sweet caramelized onions, and savory broth topped with slices of crusty baguette and gooey melted Gruyere cheese. Serve the dish with a simple green salad, bacon-wrapped asparagus, or fried cabbage for a cozy and flavorful weeknight dinner.
Table of Contents
If you love French onion recipes, be sure to try this easy French onion soup, a French onion pasta bake with spinach and mushrooms, and this dump-and-bake French onion chicken, too!
How to Make French Onion Chicken Casserole | 1-Minute Video
This French onion chicken bake is a slight twist on my traditional French onion soup recipe, designed for those who prefer a meal that they can eat with a fork rather than a spoon! I’ve added chicken to make it more satisfying and appealing to the meat-lovers at the table, but the rest of the flavors and ingredients remain largely the same. It’s a classic dish made with onions, chicken, and broth.
Bowls of French onion soup are typically topped with a slice or two of crusty bread and served au gratin — sprinkled with grated cheese and browned on top. The soup tastes slightly sweet, thanks to the caramelized onions, and savory — thanks to the herbs, broth, and garlic. The toasted baguette and gooey cheese add a hearty, rich taste and texture that complements the otherwise light soup. Here, we’ve accomplished the same flavorful combination by adding a layer of crusty baguette and melted cheese on top of the chicken and onion filling.
Ingredients
This is just a quick overview of the ingredients that you’ll need for a French onion chicken bake. As always, specific measurements and step-by-step instructions are included in the printable recipe box at the bottom of the post.
- Butter: to sauté the onions. If using unsalted butter instead of salted butter, you may need to add an extra pinch of salt to the onions.
- Onions: I like sweet onions, such as Vidalia, which offer a nice contrast to the savory broth. For slightly less sweetness, use yellow onions.
- Kosher salt and ground black pepper: the total amount necessary will vary depending on the saltiness of your broth and on your personal preference. Season to taste!
- Fresh thyme sprigs: add a nice earthy flavor. You can sub with dried thyme leaves if that’s all that you have available.
- Garlic: for savory flavor. You can substitute with a little bit of garlic powder.
- Balsamic vinegar: a splash of acidic vinegar really brightens up the dish.
- Worcestershire sauce: for savory, umami flavor that adds richness to the broth.
- Chicken: I use a store-bought rotisserie chicken for a quick, weeknight shortcut.
- Broth: both chicken broth and beef broth work well, so pick whichever you prefer. Use low sodium beef broth or low sodium chicken broth if you’re concerned about the salt in your dish.
- Baguette: a good crusty loaf of bread is the perfect topping for the casserole. You can make your own baguette with this easy recipe, or purchase one at the bakery.
- Gruyere cheese: the top will become ooey, gooey, and flavorful under the broiler.
Which Chicken to Use for a Casserole?
You’ll need cooked chicken for this recipe, and a variety of options will work. Pick the most convenient method for you:
- Boiled and Pulled Chicken: Boil about 1 ½ lbs. of boneless skinless chicken breasts or chicken thighs until cooked through (about 15-20 minutes). When cool enough to handle, chop or pull the juicy chicken breasts and use in the recipe. I find that 1 ½ lbs. of chicken breasts yields about 3 cups of pulled chicken, but there’s some flexibility here — it doesn’t need to be exact.
- Rotisserie Chicken: This is a great shortcut! Purchase a large rotisserie chicken (or two small chickens) from the grocery store, shred the meat, and use in the recipe as instructed.
- Leftover Chicken: If you have leftover grilled or baked chicken from a previous meal, put those extras to good use in this casserole.
- Canned Chicken: Yep, you can even use canned chicken in this casserole!
What’s the Best Casserole Dish to Use?
We rounded up the best casserole dishes you can buy, including 2 that I personally own and love! While I use different-sized casserole dishes for different meals, the Staub Ceramic Rectangular Baking Dish earned the top spot. You can buy it on Amazon for $78.95 or at Target for $79.95. That said, I also love the beautiful, Scandinavian style of the Dansk Kobenstyle Baker, available for $135.
The Best Cheese for French Onion Chicken Casserole
A traditional French onion soup recipe typically calls for Comté (or Gruyère de Comté), but you can also use Swiss Gruyère, Emmentaler, or Fontina cheeses. I tend to use a regular block of Swiss cheese, provolone cheese, mozzarella cheese, or even Gouda cheese, since that’s what’s readily available in my little grocery store. A sprinkling of Parmesan cheese is also delicious!
How to Make French Onion Baked Chicken
This simple supper comes together in one skillet with just 10 minutes of prep. Take some help from a store-bought rotisserie chicken for an easy weeknight meal that’s full of traditional French onion flavor!
- Sauté Onions, Garlic, and Thyme. Cook the sliced onions with garlic and thyme in butter for about 20 minutes, stirring frequently, until the onions are thick, sweet, and golden brown. Add the vinegar and Worcestershire sauce; cook for 1 more minute.
- Add Chicken and Broth. Stir in the chicken and broth, scraping any browned bits from the bottom of the pan. Those little bits add so much flavor to the casserole! Season with salt and pepper.
- Boil. Bring the liquid to a boil, and then remove the pan from the heat.
- Broil with Bread and Cheese. Arrange the toasted baguette slices on top of the chicken mixture. Sprinkle with cheese, and then transfer the skillet to the broiler for 3-5 minutes, or until the cheese is melted and starting to brown. Keep a close eye on the pan while it’s under the broiler, because that cheese and bread can burn very quickly.
Serving Suggestions
Pair this easy chicken casserole with any of these sides:
- 3-Ingredient Buttermilk Biscuits, Sweet Potato Biscuits, Flaky Biscuits, Cheese Biscuits, or Drop Biscuits
- Cranberry Muffins or Apple Muffins
- Pumpkin Bread or Pumpkin Muffins
- Green Salad with Red Wine Vinaigrette, Mixed Greens with Dijon Vinaigrette, Caesar Salad, or our favorite House Salad with Candied Pecans
- Southern Fried Apples, Baked Apple Slices, or Applesauce
- Roasted Asparagus, Bacon Wrapped Asparagus, or Sauteed Asparagus
- Amish Green Beans with Brown Butter or Southern-Style Green Beans
- Parmesan Roasted Cauliflower or Roasted Broccoli
- Oven-Roasted Brussels Sprouts with Bacon or Roasted Root Vegetables
- Brown Sugar Glazed Carrots
- Cranberry Sauce
Preparation and Storage
- Make Ahead: you can prepare the chicken and onion mixture up to 1 day ahead. Cover and store in the refrigerator until ready to bake. Before baking, heat the dish gently on the stovetop until warmed through. Then top with bread and cheese and broil according to recipe directions.
- Leftovers will keep in an airtight container in the fridge for 3-4 days, or in the freezer for up to 3 months. The bread will get soggy as the dish sits, however, so this meal is best enjoyed immediately.
- How to Reheat: cover the dish loosely with foil. Bake in a 350°F oven just until warmed through, about 15-20 minutes. You can also microwave individual portions for 1-2 minutes, or until they reach the desired temperature.
Recipe Variations
- If you don’t have an oven-safe skillet, no problem! Just transfer the chicken and onion mixture to a 2-quart baking dish (or other similar 9-inch or 8-inch square casserole dish) before adding the bread and cheese topping.
- Use 2 cans of drained, rinsed white beans in lieu of the chicken.
- Swap out the Gruyere cheese and use Swiss, mozzarella, provolone, or Gouda cheese instead.
- Use beef broth or beef stock, chicken broth or chicken stock — they all work well in this dish.
- Instead of the balsamic vinegar, try adding a splash of dry sherry.
- In lieu of Vidalia onions, you can use yellow onions for a less sweet taste, or red onions for a bolder, zestier flavor.
tips for the best french onion chicken recipe
- I use this 2.25-quart Le Creuset braiser, which is an oven-safe skillet with a lid. A 9-inch or 10-inch cast iron skillet will also work well.
- Stir the onions regularly and add water frequently to ensure that the onions don’t burn. If they start to get too dark too quickly, just lower the temperature and cook them over medium heat or medium-low heat.
- Choose a high-quality crusty bread (such as a French baguette) for topping your casserole. It only needs to be toasted lightly, because it will go under the broiler and get even darker and crispier on the edges.
- Keep a close eye on the dish while it’s under the broiler, since the bread and cheese can burn quickly.
- Garnish each serving with fresh herbs for a bright, colorful touch. Good options include thyme, parsley, rosemary, or chives.
More Chicken Casserole Recipes to Try
French Onion Chicken Bake
Equipment
- Oven Safe Skillet (this Le Creuset one is oven-safe up to 500 F)
Ingredients
- 2 tablespoons salted butter
- 1 lb. Vidalia onions, or other sweet onions, thinly sliced (about 2 medium onions)
- Kosher salt and ground black pepper, to taste
- 1 teaspoon minced fresh thyme leaves (or about ¼ teaspoon dried thyme)
- 1 clove garlic, peeled and minced or pressed
- 1 tablespoon balsamic vinegar
- 1 teaspoon Worcestershire sauce
- 3 cups cooked, diced or shredded chicken (such as the meat from a rotisserie chicken)
- 1 cup chicken stock or beef broth
- 9 slices crusty French baguette (or other similar bread), sliced about ½-inch thick
- 1 cup grated Gruyere cheese (or sub with grated Swiss cheese)
- Optional, for serving: chopped fresh thyme or parsley for garnish
Instructions
- Preheat oven to 475°F. Arrange the bread slices on a baking sheet and toast lightly in the oven, about 4-5 minutes. Set aside.
- Meanwhile, in a medium ovenproof skillet, melt butter over medium-high heat. Add the onions and season with salt and pepper. Cover with a lid and cook, stirring occasionally, until the onions are softened, about 3-5 minutes.
- Remove the lid, stir in the thyme and garlic, and continue to cook and stir until the onions are deep golden brown, about 15 minutes. As the onions cook, add a tablespoon of water; stir. Once the water evaporates, repeat the process with additional tablespoons of water. This prevents the onions and garlic from burning, and it speeds up the caramelization.
- Add the vinegar and Worcestershire sauce; cook for 1 more minute.
- Stir in the chicken and broth; taste and season with salt and pepper. Bring the mixture to a boil, then remove from the heat.
- Turn the oven to “BROIL.”
- Arrange the toasted bread slices on top of the chicken and onion mixture. Sprinkle the cheese over top.
- Place the skillet under the broiler for about 3-5 minutes, until the cheese melts and starts to brown.
- Garnish with chopped fresh parsley or thyme, if desired.
Video
Notes
- I use this 2.25-quart Le Creuset braiser, which is an oven-safe skillet with a lid. A 9-inch or 10-inch cast iron skillet will also work well.
- Stir the onions regularly and add water frequently to ensure that the onions don’t burn. If they start to get too dark too quickly, just lower the temperature and cook them over medium heat or medium-low heat.
- Choose a high-quality crusty bread (such as a French baguette) for topping your casserole. It only needs to be toasted lightly, because it will go under the broiler and get even darker and crispier on the edges.
- Keep a close eye on the dish while it’s under the broiler, since the bread and cheese can burn quickly.
- Garnish each serving with fresh herbs for a bright, colorful touch. Good options include thyme, parsley, rosemary, or chives.