French Onion Chicken Thighs - Heavenly Home Cooking

This French onion chicken thighs recipe combines the flavors of French onion soup with juicy, seared chicken thighs – all in a simple stovetop dish. It’s made in just one pan for easy cleanup!

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A white enameled cast iron skillet filled with French onion chicken thighs, topped with melted Swiss cheese and caramelized onions, garnished with fresh parsley, sitting on a rustic wooden table.

These French onion chicken thighs are exactly what you need If you’re looking for a one-pan meal that’s rich, savory, and packed with flavor.

Juicy chicken thighs are simmered in a deeply caramelized onion and beef broth sauce, then topped with melted Swiss cheese for that irresistible, cheesy finish. It’s everything you love about French onion soup, but heartier and more satisfying – perfect for a cozy dinner at home.

I first made this dish on a chilly evening when I was craving something warm and comforting but didn’t want to spend hours in the kitchen. The magic happens in just one skillet, making cleanup a breeze, and the flavors are absolutely restaurant-worthy. My husband took one bite and immediately declared it a new favorite!

This dish pairs perfectly with our truffle mashed potatoes recipe to soak up all of the delicious sauce.

Reasons to Love This Recipe

Unbelievably flavorful. The slow-cooked onions create a rich, caramelized base that takes the sauce to the next level.
Easy stovetop cooking. No need to turn on the oven! Everything simmers to perfection in just one pan.
Comfort food at its best. It’s like French onion soup met a juicy, pan-seared chicken thigh and fell in love.
Pairs with anything. Serve it with mashed potatoes, rice, or crusty bread to soak up every bit of that flavorful sauce.

Ingredient Overview

Be sure to check out the full recipe and ingredient list below

A top-down view of labeled ingredients for French onion chicken thighs, including boneless chicken thighs, sliced onions, beef broth, Swiss cheese, balsamic vinegar, butter, olive oil, garlic powder, dried thyme, and flour.

Before we jump into cooking, let’s break down the key ingredients in this recipe and how they work together to create those deep, savory flavors. If you’re new to cooking or just want to know what can be swapped, here’s everything you need to know!

Yellow Onions. Onions are the star of the dish. They are slow-cooked until they’re deeply caramelized, bringing out their natural sweetness. Sweet onions (like Vidalia) will make the dish even sweeter, while red onions will give a slightly different depth of flavor. If using white onions, they have a sharper bite but still work.
Butter & Olive Oil. A combination of butter and olive oil is best for caramelizing the onions. Butter adds richness, while olive oil prevents burning. You can use all butter for a richer flavor (keep an eye on it so it doesn’t burn – lower heat is best) or all olive oil for a lighter version. Avocado oil also works.
Boneless, Skinless Chicken Thighs. Thighs stay moist and flavorful as they simmer in the sauce. Bone-in thighs can be used but will require 5-7 extra minutes of cooking time. Chicken breasts work too but may need less simmering time to avoid drying out.
Garlic Powder & Dried Thyme. These seasonings add depth to the dish. Fresh minced garlic (1 clove = ¼ teaspoon garlic powder) and fresh thyme (3 sprigs = 1½ teaspoon dried) can be used for even more flavor.
Salt & Black Pepper. Enhances all the flavors – taste and adjust as needed!
All-Purpose Flour. (For Thickening the Sauce) Flour helps create a lightly thickened sauce that coats the chicken beautifully. If gluten-free, use cornstarch (½ tablespoon cornstarch for every 1 tablespoon flour) or a gluten-free all-purpose flour blend.
Beef Broth. Beef broth creates the deep, flavorful sauce that mimics French onion soup. Chicken broth works if needed, but the flavor will be milder. For more intense flavor, use ½ cup broth + ¾ cup water + 1 teaspoon Worcestershire sauce.
Balsamic Vinegar. Balsamic vinegar gives the dish a subtle tanginess and extra richness to balance the onions. Red wine vinegar or Worcestershire sauce can be used in a pinch, though the flavor will be slightly different.
Swiss Cheese. Swiss cheese completes the dish, just like the broiled cheese topping on French onion soup! Gruyère (more traditional for French onion flavors), provolone (milder), or mozzarella (stretchier texture).
Fresh Parsley. Fresh parsley adds a fresh contrast to the rich, cheesy dish. Chopped fresh thyme or a sprinkle of green onions work too.

Pro Tip

If you want an even richer sauce, stir in a splash of heavy cream or a little Dijon mustard at the end!

Step-By-Step Instructions with Photos

This is a brief overview. Be sure to check out the full recipe and ingredient list below

A white enameled cast iron skillet on a marble countertop with melted butter and oil beginning to brown, creating a flavorful base for cooking. — **Step 1:** Heat butter and olive oil in a large skillet over medium heat.

A white enameled cast iron skillet filled with thinly sliced raw onions, ready to be caramelized in melted butter and oil. — **Step 2:** Add onions and a pinch of salt. Cook for 5 minutes, stirring occasionally. Reduce heat to medium-low and continue cooking for 35–40 minutes until caramelized, stirring occasionally. Adjust heat if needed to prevent burning. **Shortcut:** Add ½ teaspoon sugar to speed up browning.

A white enameled cast iron skillet filled with deeply caramelized onions, golden brown with a rich, dark color, ready to be used in the French onion chicken recipe. — Onions should be deep golden brown and jammy in texture.

A hand holding a small bowl of balsamic vinegar, ready to be poured into a white enameled cast iron skillet filled with deeply caramelized onions. — **Step 3:** Stir in balsamic vinegar and cook for 2 minutes. Remove onions from the skillet and set aside.

Six raw boneless, skinless chicken thighs on a white cutting board, seasoned with a blend of dried herbs and spices, ready for cooking. — **Step 4:** Increase heat to medium-high, adding more oil if needed.
**Step 5:** Season chicken thighs with garlic powder, thyme, salt, and pepper. Let sit for 10 minutes for even searing.

A white enameled cast iron skillet with three seasoned raw chicken thighs placed inside, ready to be seared for the French onion chicken recipe. — **Step 6:** Sear chicken for 2–3 minutes per side

A white enameled cast iron skillet with three seasoned chicken thighs that have been seared to a golden brown, developing a flavorful crust. — Thighs should be golden brown but not fully cooked. Cook in batches if needed for a proper sear. Remove and set aside.

A white enameled cast iron skillet with browned bits from searing chicken, with a small amount of flour added to create a roux for thickening the sauce. — Stir 1 tablespoon of flour into the skillet and cook for 1 minute.

A hand pouring beef broth from a glass measuring cup into a white enameled cast iron skillet with browned bits and flour, creating a rich sauce base. — Gradually whisk in 1¼ cups beef broth, stirring constantly to prevent lumps. Simmer for 1–2 minutes until slightly thickened. Add more broth if needed to adjust consistency.

A white enameled cast iron skillet filled with a rich, dark onion and beef broth sauce, simmering and thickening to create a flavorful base for French onion chicken. — **Step 8:** Add the caramelized onions back to the skillet, spreading them evenly into the sauce.

A white enameled cast iron skillet with six seared chicken thighs nestled into a rich, dark onion and beef broth sauce, simmering to absorb the flavors. — **Step 9:** Place the seared chicken thighs back into the skillet, nestling them into the onions and broth.

A hand placing a lid on a white enameled cast iron skillet filled with seared chicken thighs simmering in a rich onion and beef broth sauce. — Cover and simmer on medium-low for 15 minutes, until the chicken reaches 165 F (74 C).

A white enameled cast iron skillet filled with French onion chicken, topped with six slices of Swiss cheese, ready to melt into the rich onion sauce. — **Step 10:** Top each cooked chicken thigh with a slice of Swiss cheese.

A hand placing a lid on a white enameled cast iron skillet filled with French onion chicken, topped with Swiss cheese, allowing it to melt into the rich onion sauce. — Cover and let cook for 2–3 minutes until the cheese is melted and gooey. Turn off the heat for a softer melt.

Tips for Success

Be Patient with the Onions. Caramelizing onions takes time, but it’s worth it. Cooking them low and slow allows their natural sugars to develop, creating savory-sweet flavor. Stir occasionally to prevent burning, and if they start to stick, add a splash of water or broth to deglaze the pan. If you’re short on time, adding ½ teaspoon of sugar can speed up the caramelization process slightly.
Get a Good Sear on the Chicken. A golden-brown sear means more flavor. Before adding the chicken to the pan, pat it dry with a paper towel to remove excess moisture. Don’t move the chicken around too much while searing – let it develop a crust before flipping.
Deglaze for Maximum Flavor. After searing the chicken, there will be browned bits (fond) stuck to the bottom of the pan – don’t waste them. When you add broth, scrape up all those flavorful bits to incorporate into the sauce.
Keep the Sauce the Right Consistency. If the sauce gets too thick, add an extra splash of broth to loosen it. If the sauce is too thin, let it simmer uncovered for a few minutes longer to reduce.
Use the Right Cheese. Swiss cheese melts beautifully, but for a stronger French onion soup flavor, use Gruyère instead. If you want an extra cheesy finish, broil the skillet for two minutes after adding the cheese until it bubbles and turns golden brown.
Taste and Adjust Seasoning. Since beef broth and cheese are both salty, start with less salt when seasoning the dish and adjust at the end. A small splash of balsamic vinegar at the end can brighten up the flavors even more.
Make it Your Own. Love mushrooms? Add sliced mushrooms along with the onions for even more flavor. Prefer a creamier sauce? Stir in a splash of heavy cream just before serving. Want a crispy topping? Transfer the skillet to the oven and broil for a few minutes after melting the cheese.
Let It Rest Before Serving. Once everything is done, let the dish sit for two to three minutes before serving. This allows the flavors to settle, and the sauce to thicken slightly.

A spoon lifting a cheesy French onion chicken thigh from a skillet, with melted cheese stretching from the pan.

Storage

Refrigerating Leftovers

Allow the dish to cool completely before storing.
Transfer leftovers to an airtight container and store in the refrigerator for up to 3 days.
Store the chicken and sauce together.

Freezing (Not Recommended)

Due to the cheese and caramelized onions, this dish does not freeze well. The texture of the onions and cheese may change when thawed.
If you must freeze it, store the chicken and sauce separately from the cheese and thaw overnight in the refrigerator before reheating.

Reheating

Broiler: If the cheese needs to be melted again, place the chicken under the broiler for 1-2 minutes until bubbly.

Stovetop (Recommended): Add a splash of broth to a skillet over low heat and warm the chicken gently, covered, until heated through. This helps maintain the sauce’s consistency and prevents the chicken from drying out.

Microwave (Faster Option): Place the chicken and sauce in a microwave-safe dish, cover lightly, and heat in 30-second increments until warmed through. Add a bit of broth if needed to keep the sauce from thickening too much.

Close-up of French onion chicken thighs in a skillet, topped with caramelized onions and melted Swiss cheese, with a rich, savory sauce.

Pairing Suggestions

Our Favorite

Chicken Recipes

French onion chicken thigh served over mashed potatoes on a white plate, topped with caramelized onions and rich gravy.

Prep Time:10 minutes

Cook Time:50 minutes

Total Time:1 hour

3 tablespoons butter
1½ tablespoons olive oil
3 large yellow onions or 5–6 small, thinly sliced (Note 1)
1½ tablespoons balsamic vinegar
6 boneless, skinless chicken thighs (Note 2)
1½ teaspoons garlic powder
1½ teaspoons dried thyme
Salt and pepper to taste
1 tablespoon all-purpose flour
1¼ cups beef broth (Note 3)
6 slices Swiss cheese 1 per chicken thigh (Note 4)
Fresh parsley chopped (optional, for garnish)

Heat 3 tablespoons butter and 1½ tablespoons olive oil in a large, deep skillet over medium heat.
Add the sliced onions and a pinch of salt. Cook, stirring occasionally, for 5 minutes.Tip: Low and slow is key! If the onions are browning too quickly, reduce the heat. Stir occasionally to prevent burning. (Note 5)Lower the heat to medium-low and continue cooking for 35–40 minutes, stirring occasionally, until the onions are golden brown and caramelized.Check at 30 minutes and adjust heat as needed to avoid burning. (Note 6)Shortcut: Add ½ teaspoon of sugar to help the onions brown faster. (Note 7)

3 large yellow onions
Stir in the 1½ tablespoons balsamic vinegar and cook for another 2 minutes.Remove the onions from the skillet and set aside.
In the same skillet, increase heat to medium-high and add a little more oil if needed (about 1 teaspoon at a time).
Season the 6 boneless, skinless chicken thighs with 1½ teaspoons garlic powder, 1½ teaspoons dried thyme, Salt and pepper.Tip: Let the chicken thighs sit at room temperature for 10 minutes before cooking for even searing. (Note 8)
Sear the chicken for 2–3 minutes per side until golden brown but not fully cooked. Remove and set aside.Tip: Don’t overcrowd the pan – cook in batches if needed to get a proper sear. (Note 9)
Reduce heat to medium.Sprinkle 1 tablespoon all-purpose flour into the skillet and stir for 1 minute to cook out the raw flour taste.Slowly whisk in 1¼ cups beef broth, stirring constantly to prevent lumps.Tip: If the sauce thickens too much, add a splash of extra broth to loosen it up. (Note 10)Simmer for 1–2 minutes until the broth slightly thickens.
Return the caramelized onions to the skillet, spreading them evenly in the sauce.
Nestle the seared chicken thighs into the onions and broth.Cover with a lid and let simmer on medium-low heat for 15 minutes, or until the chicken reaches an internal temperature of 165 F (74 C). (Note 11)
Once the chicken is fully cooked, place 1 slice of Swiss cheese on top of each piece.Cover the skillet again and let it cook for 2–3 more minutes, until the cheese is melted and gooey.Tip: Turn off the heat and let the residual warmth melt the cheese if you prefer a softer melt. (Note 12)

6 slices Swiss cheese
Garnish with fresh parsley, if desired.Serve with garlic mashed potatoes, rice, or crusty bread to soak up the rich sauce.

Yellow onions work best, but sweet onions will add an extra depth of flavor.
Boneless, skinless thighs work best for this recipe. Bone-in thighs can be used but may require a longer cooking time (5–7 minutes longer).
Use a high-quality broth for the best flavor. Low-sodium broth is recommended to control salt levels.
Gruyère or Provolone can be used as an alternative.
Patience is key! Cooking too fast will burn them rather than caramelize.
Check onions at 30 minutes and adjust the heat to prevent burning.
Adding a small amount of sugar can help speed up the caramelization process.
Room temperature chicken helps with even cooking and a better sear.
Overcrowding prevents a proper sear, leading to steaming instead.
If the sauce becomes too thick, add extra broth a little at a time.
If using bone-in thighs, increase simmering time by 5–7 minutes.
Letting it melt with the lid on ensures a smooth, gooey texture.
For the best texture, reheat under the broiler to remelt the cheese perfectly.

Servings: 6 servings

Calories: 327kcal

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