French Onion Chicken Thighs

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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.

Ingredient Overview

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.

Step-By-Step Instructions with Photos

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.

Pairing Suggestions

• Truffle Mashed Potatoes
• Parmesan Butter Noodles
• Garlic Rosemary Potatoes
• Garlic Butter Mushrooms
• Garlic Parmesan Rice

French Onion Chicken Thighs Recipe

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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Prep Time:10 minutes mins

Cook Time:50 minutes mins

Total Time:1 hour hr

Equipment

Chef's knife

Cutting board

Heatproof spatula

Heavy-bottomed deep skillet with lid

Liquid measuring cups

Measuring spoons

Tongs

Wire whisk

Wooden spoon

Ingredients

• 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)

Instructions

• 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.

Notes

1. Yellow onions work best, but sweet onions will add an extra depth of flavor.
2. 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).
3. Use a high-quality broth for the best flavor. Low-sodium broth is recommended to control salt levels.
4. Gruyère or Provolone can be used as an alternative.
5. Patience is key! Cooking too fast will burn them rather than caramelize.
6. Check onions at 30 minutes and adjust the heat to prevent burning.
7. Adding a small amount of sugar can help speed up the caramelization process.
8. Room temperature chicken helps with even cooking and a better sear.
9. Overcrowding prevents a proper sear, leading to steaming instead.
10. If the sauce becomes too thick, add extra broth a little at a time.
11. If using bone-in thighs, increase simmering time by 5–7 minutes.
12. Letting it melt with the lid on ensures a smooth, gooey texture.
13. For the best texture, reheat under the broiler to remelt the cheese perfectly.

Nutrition

Calories: 327kcal | Carbohydrates: 10g | Protein: 28g | Fat: 19g | Saturated Fat: 8g | Polyunsaturated Fat: 2g | Monounsaturated Fat: 7g | Trans Fat: 0.3g | Cholesterol: 138mg | Sodium: 368mg | Potassium: 444mg | Fiber: 1g | Sugar: 4g | Vitamin A: 354IU | Vitamin C: 6mg | Calcium: 190mg | Iron: 2mg

Servings: 6 servings

Calories: 327kcal

Author: Sandra

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