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This French Onion Chicken Bake recipe has all the flavor of your favorite soup with the convenience of a high-protein skillet dinner. Onions are quickly caramelized on the stovetop before being combined with chicken and veggies and topped with melty cheese.
Low-carb, gluten-free, and made in under an hour with only 25 minutes of hands-on cooking, this French onion baked chicken is a winning recipe!
Quick and Easy French Onion Chicken Bake
We love French onion soup! However, we’ve never loved how labor-intensive the dish is or how long it takes (which is why we have a recipe for a slow cooker French onion soup).
But this French onion chicken bake? It’s like the best of both worlds; all that classic soup flavor in a heartier convenient weeknight dinner format. We also skipped the bread on this one, relying on perfectly cooked juicy chicken breasts to eat up all that caramelized onion flavor.
The cheese is optional here, but highly encouraged. Filling and flavorful, this is one recipe that never leaves you with any leftovers!
Ingredients Needed and Substitutions
*Scroll down to the recipe card for the full recipe and ingredient list!
- Butter: I recommend grass-fed butter for the best taste.
- Oil: I typically use avocado oil or olive oil.
- Aromatics: Yellow onions are the star of the show! Then, we add garlic and fresh thyme to enhance the sweet, savory flavor.
- Beef Stock: This is what creates a rich, saucy soup-like taste and texture. I recommend using low-sodium beef broth or stock to prevent the dish from tasting too salty.
- Dijon Mustard: A staple in any French onion recipe, the tanginess of Dijon works to really enhance the onions.
- Chicken: I use boneless skinless chicken breasts, but chicken cutlets or boneless skinless chicken thighs also work. Look for pieces that are roughly the same size to ensure even cooking!
- Cauliflower: I love to sneak in cauliflower florets for a boost of nutrients! However, you can omit them completely. Or, substitute halved baby potatoes for a heartier meal.
- Cheese: Mozzarella cheese or gruyere cheese will give you the classic savory, salty flavor you look for in French onion soup. However, provolone and Swiss cheese also taste great. Of course, you can also omit the cheese completely, but it’s my favorite part!
Where I Buy My Meat
- 100% Grass-Fed, Grass-Finished Beef
- Free-Range Organic Chicken
- Humanely Raised Pork
- Wild-Caught Seafood
Delivered to your door! The latest ButcherBox deal can be found right here!
Kitchen Tools I Use
How to Make This French Onion Chicken Bake
- Caramelize the onions: Heat the butter and oil in a large oven-safe skillet over medium-high heat. Then, add the sliced onions, and cook undisturbed until they begin to sweat and are brown in places. Reduce the heat to medium-low, add the salt, and continue to cook until the onions soften, stirring occasionally.
- Sauté: Add the garlic and thyme, and cook until fragrant. Then, pour in the beef stock and mustard, scraping up any browned bits from the bottom. This is where all the best flavor comes from!
- Simmer: Continue to cook until the liquid reduces by half, and set half the onion mixture aside.
- Combine: Add the cauliflower to the skillet, mixing to combine it with the onions. Then, season the chicken with salt and pepper, and nestle it between the veggies. Sprinkle the remaining onions over the chicken.
- Bake: Transfer the skillet to a preheated oven, and bake until the chicken cooks through.
- Broil: Sprinkle the shredded cheese on top. Then, broil to melt the cheese and create a golden brown topping. Be careful not to burn!
- Serve: Remove the thyme sprigs from the pan, and enjoy your French onion chicken casserole while it’s warm!
Caramelized Onions
Traditionally, caramelized onions are cooked over a low flame for a long period of time. The water is slowly cooked out of the onions, and you are left with a sweet, almost jam-like consistency.
However, because we wanted this French onion bake to be a weeknight dinner that still has all that caramelized onion goodness we’re making “quick” caramelized onions. You still get all the incredible flavor just with a fraction of the time involved!
Storage
- Refrigerator: Transfer leftovers to an airtight container, and store them in the refrigerator for up to 5 days.
- Freezer: Omit the cheese top. Then, transfer leftovers to a freezer-safe container, and freeze for 2-3 months. Thaw in the fridge overnight, add the cheese, and broil when you’re ready to serve.
- Reheat: Warm leftovers in the microwave or in a skillet over medium heat.
FAQs
The safe temperature for chicken to be cooked to is 165ºF. However, the chicken will continue to cook for a few minutes after it has been pulled out of the oven. So, it’s a safe bet to remove the chicken from the oven a few degrees before it hits that temperature.
The surest way to know if a chicken breast is cooked through is to use an instant-read thermometer. Insert it into the thickest part of the chicken breast, and wait about 3 seconds for it to read the degree. We pull our chicken breasts out at 160ºF and let the dish sit, lightly covered with tinfoil for 5-10 minutes so the chicken can rest.
Yes! If you don’t have an oven-safe skillet, simply prepare the ingredients on the stovetop. Then, transfer them to a 9×13 baking dish before broiling.
You can easily serve this baked French onion chicken recipe on its own as a filling, low-carb meal. However, if you’re feeding a hungry crowd, it’s also great with sides like Instant Pot mashed potatoes, gluten-free garlic bread, a Caesar salad recipe, air fryer asparagus, or garlicky blistered green beans.
More Chicken Recipes To Try
French Onion Chicken Bake
Ingredients
- 1 tablespoon butter
- 1 tablespoon oil
- 5 medium onions sliced thin
- ½ teaspoon fine sea salt
- 3 garlic cloves minced
- 3 sprigs fresh thyme or 1 teaspoon dried
- ½ cup beef stock
- 1 tablespoon dijon mustard
- 3 cups cauliflower florets see note
- 4 boneless skinless chicken breasts
- 1 cup shredded mozzarella or gruyere cheese
Instructions
- Preheat oven to 400ºF.
- Heat butter and oil over medium high heat in a large oven safe skillet (12 inches or more, see note). Add onions and cook undisturbed for 5 minutes, until onions start to sweat and have browned in places. Reduce heat to medium low, add salt and and cook for an additional 10-15 minutes, stirring occasionally, until the onions have softened. Add garlic and thyme and cook for an additional 2 minutes. Add in beef stock and mustard and scrape up any browned bits and continue to cook until the liquid has reduced by about half, about 2 minutes.1 tablespoon butter, 1 tablespoon oil, ½ teaspoon fine sea salt, 5 medium onions, 3 garlic cloves, 3 sprigs fresh thyme, ½ cup beef stock, 1 tablespoon dijon mustard
- Set aside ½ cup of the onion mixture. Add the cauliflower to the skillet and mix together with the onions.3 cups cauliflower florets
- Season the chicken with salt and pepper then nestle the chicken in the skillet. Divide the set aside onions on top of the chicken.4 boneless
- Place in the preheated oven and bake until chicken is cooked through, about 20 minutes.
- Preheat the broiler. Sprinkle the shredded cheese on top of the chicken and place under the broiler until the cheese is melty, about 1 minute.1 cup shredded mozzarella or gruyere cheese
- Remove thyme sprigs and serve.
Notes
- Refrigerator: Transfer leftovers to an airtight container, and store them in the refrigerator for up to 5 days.
- Freezer: Omit the cheese top. Then, transfer leftovers to a freezer-safe container, and freeze for 2-3 months. Thaw in the fridge overnight, add the cheese, and broil when you’re ready to serve.
- Reheat: Warm leftovers in the microwave or in a skillet over medium heat.
Amazing! Such an easy dish to make with ingredients I usually have on hand. So much flavor!!
Would eliminating the mustard ruin this?
No, it will just have a less nuanced flavor. Won’t ruin the integrity of it so feel free to omit if you want.
This was AMAZING and so quick and easy. I halved it because I wasn’t sure how it would be leftover but had some for lunch today and it held up so well. This will be added to a regular rotation for sure!
Another winner from LCK! Added in some baby Yukon gold potatoes to stretch it to two meals for my husband and I.
YES!!!!
If you’re thinking about making this, stop thinking and make it. It’s so, so, good. Really easy to make – the hardest part was cutting onions and being blinded by tears. Great addition to weeknight dinners and especially great if you want a hearty – but light – meal as the weather gets chilly!
I find it an absolutely perfect idea for dinner. You know, when I get bored from usual recipes, I start surfing the Internet to find something proper and interesting and then make a list of dishes I am going to cook. Now your recipe is on top and I am sure to prepare it right today. I like the combination of ingredients and that I can have a tasty, fragrant and hearty dish for less than an hour. Thank you very much for this clear and detailed recipe! Your blog is a real treasury, keep it up!
Wow! These recipes look really yummy and easy to make. Thanks for sharing the recipe.