French Onion Chicken

French onion soup flavors, but make it dinner. This French Onion Chicken has juicy seared chicken, a rich onion sauce, and a melty layer of Gruyère that turns bubbly and golden in the oven. The onions cook down until they’re soft, sweet, and deeply browned, then the broth turns into a spoonable sauce that clings to every bite.

Your favorite soup is becoming a complete meal

This recipe is basically the dinner version of that first bite of French onion soup when the cheese is still stretchy and the onions taste sweet and deeply savory. You get the same comfort, but instead of a bowl and a spoon, you’ve got golden seared chicken that soaks up all that flavor.

Here’s what makes it special. You cook the onions with a splash of broth so they soften and brown faster, then you thicken the pan sauce just enough so it coats the chicken instead of running off. After that, the Gruyère goes on and everything finishes in the oven so the top gets melty and bubbly.

I love this one when I want something cozy that still feels like a real dinner. It looks impressive in the skillet, but the steps are simple, and the ingredient list is short. Plus, the leftovers reheat well, which is always a win.

If you love French onion flavors, add Easy French Onion Soup and Sausage French Onion Pasta to your list.

Ingredients in french onion chicken

You don’t need much to make this French Onion Chicken! I usually always have chicken on hand and the rest of the ingredients are pantry staples and Gruyére cheese. So simple, yet SO delicious!

• Butter: you’ll need 3 tbsp butter, 2 tbsp for the onions and 1 tbsp for searing the chicken. Ghee works well, too.
• Onions: you’ll need 2 large onions, sliced very thin so they cook down quickly and evenly. White or yellow onions are best here.
• Broth: you’ll need 1 cup broth to build the sauce. Beef broth gives the most classic French onion flavor, chicken broth also works.
• Chicken breasts: you’ll need 4 medium chicken breasts. If they’re extra thick, pound them so they cook evenly.
• Dried thyme: you’ll need 1 tsp dried thyme for a cozy, savory note. Italian seasoning is a good backup.
• Salt: you’ll need 1 tsp salt. If your broth is salty, start with a little less and adjust at the end.
• Black pepper: you’ll need 1 tsp pepper for balance and bite.
• Arrowroot powder: you’ll need 1 tbsp arrowroot powder to thicken the sauce fast. Cornstarch is a 1:1 swap.
• Gruyère cheese: you’ll need 1 cup grated Gruyère for that classic melt. Mozzarella is a solid substitute if that’s what you have.

Tools needed to make this recipe

• Large oven-safe skillet
• Cutting board + sharp knife
• Meat mallet or rolling pin
• Small mixing bowl + whisk
• Spoon or spatula
• Measuring cups + spoons

How to make this french onion chicken recipe

Preheat the oven to 400°F. This finishes quickly once everything is assembled, so having the oven hot matters.

Heat 2 tbsp butter in a large skillet over medium-high heat. Add the sliced onions and ¼ cup of the broth, then cook for 15–20 minutes, stirring often, until browned and softened. If the onions start sticking, add a small splash of broth and scrape the pan. Those browned bits add a lot of flavor to the sauce.

While the onions cook, pound the chicken breasts until they’re an even thickness, about 1 inch all around. This keeps the chicken juicy and helps it reach temperature at the same time. Season both sides with thyme, salt, and pepper.

Transfer the onions to a bowl. Add the remaining 1 tbsp butter to the skillet, then sear the chicken for 5 minutes per side until golden. You’re building color here, not cooking it through. Move the chicken to a plate and reduce heat to medium-low.

In a small bowl, whisk together the remaining ¾ cup broth with 1 tbsp arrowroot powder until smooth. Add the onions back to the skillet, then pour in the broth mixture. Whisk and cook 2–3 minutes until the sauce thickens and looks glossy. If it gets too thick, whisk in a tablespoon or two of broth until it’s spoonable.

Nestle the chicken back into the skillet and spoon the onion sauce over each piece. Sprinkle the Gruyère evenly over the chicken, then transfer the skillet to the oven. Bake 8–10 minutes, until the chicken reaches 165°F in the thickest part.

Below are some common French Onion Chicken questions. Don’t see the answer you’re looking for? Leave a comment at the bottom of this post! I’ll be happy to help.

WHAT SHOULD I SERVE WITH FRENCH ONION CHICKEN?

Go for something that can soak up extra sauce, like mashed potatoes, rice, or roasted potatoes. For veggies, broccoli, asparagus, or Brussels sprouts are all great, and a simple green salad keeps things fresh.

WHAT ARE THE BEST ONIONS TO USE?

White onions are classic for French onion flavor because they cook down sweet and mellow. Yellow onions also work and bring a slightly deeper onion taste.

MY ONIONS ARE STICKING, WHAT SHOULD I DO?

Turn the heat down slightly and add a splash of broth or water. Scrape up the browned bits as you stir, they’ll dissolve into the onions and make the sauce taste even better.

WHY DO I NEED TO POUND THE CHICKEN?

It helps the chicken cook evenly and stay juicy. Thick spots tend to dry out on the outside before the center is done, and pounding prevents that.

MY SAUCE GOT TOO THICK, HOW DO I FIX IT?

Whisk in broth 1 tablespoon at a time until it’s glossy and spoonable again. It should coat the chicken, not clump.

CAN I USE MOZZARELLA INSTEAD OF GRUYÈRE?

Yes. Gruyère is nutty and traditional, mozzarella melts beautifully and still tastes great here. Swiss is another good option.

CAN I USE CHICKEN THIGHS INSTEAD OF BREASTS?

Yes, boneless skinless thighs work well and stay very juicy. Bake until the thickest piece reaches 165°F.

I DON’T HAVE AN OVEN-SAFE SKILLET, WHAT CAN I DO?

No problem. After you thicken the sauce, transfer everything to a baking dish, add the cheese, then bake as directed.

Store leftovers in an airtight container in the fridge for 3–4 days. Reheat gently in a covered skillet over low heat with a splash of broth to loosen the sauce, or microwave in short intervals until warmed through.

If you liked this recipe, you’ll want to try these!

• Healthy French Onion Dip
• French Onion Dip with Sausage
• Creamy Chicken Skillet
• Cider Braised Chicken

Recipe by Erin Morrissey and Photos by The Mindful Hapa