Pioneer Woman French Onion Chicken Casserole

This easy Pioneer Woman French Onion Chicken Casserole is a creamy and hearty meal perfect for any night of the week. It features layers of tender chicken and caramelized onions topped with crispy baguette slices and melted cheese. You can easily customize it with whatever ingredients you have on hand for a delicious family dish!

Ingredients Needed:

• 5 tablespoons salted butter, plus more for the baking dish
• 1 (10-ounce) package cremini mushrooms, thickly sliced
• 5 medium onions, thinly sliced
• 1 tablespoon fresh thyme, chopped
• ½ teaspoon kosher salt
• Black pepper, to taste
• 2 tablespoons all-purpose flour
• ½ cup dry white wine
• 3 cups low-sodium beef broth
• 2 cups chopped rotisserie chicken (skin removed)
• 1 long baguette, sliced ½ inch thick
• 2½ cups shredded Gruyère cheese (about 10 ounces)
• ½ cup grated Parmesan cheese

How To Cook French Onion Chicken Casserole:

1. Preheat the Oven: Preheat your oven to 425°F (220°C) and butter a 9-by-13-inch or 3-quart baking dish.
2. Cook the Mushrooms: In a large pot, melt 1 tablespoon of butter over medium-high heat. Add the sliced mushrooms and cook without stirring until browned on the bottom (about 2 minutes). Stir and continue cooking until browned all over (about 2-3 minutes). Remove the mushrooms to a plate.
3. Cook the Onions: Add the remaining 4 tablespoons of butter to the pot and melt over medium-low heat. Add the thinly sliced onions and cook, stirring frequently, until they become dark golden (about 20-25 minutes).
4. Combine Ingredients: Return the mushrooms to the pot, add the chopped thyme, kosher salt, and a few grinds of black pepper. Sprinkle in the flour and stir to coat the vegetables. Let it toast for a minute, then increase the heat, pour in the wine, and bring to a simmer. Add the beef broth and shredded chicken, returning to a simmer, and cook until thickened (about 3 minutes).
5. Assemble the Casserole: Ladle enough of the onion-chicken mixture into the prepared baking dish to cover the bottom. Arrange half of the baguette slices in a single layer on top. Ladle half of the remaining onion-chicken mixture over the bread and push down on the baguette slices with the bottom of the ladle to submerge them. Sprinkle with 1 cup of Gruyère cheese and ¼ cup of Parmesan cheese. Top with the remaining baguette slices in a single layer, then ladle the remaining onion-chicken mixture on top, and sprinkle with the remaining 1½ cups of Gruyère and ¼ cup of Parmesan.
6. Bake: Cover the casserole with foil, tenting it so it doesn’t touch the cheese. Place on a rimmed baking sheet and bake until bubbly (about 20 minutes). Uncover and bake until the top is browned and crusty (about 15 minutes more). Let sit for 10 minutes before serving.

Recipe Tips

• Use Fresh Ingredients: Fresh onions and herbs give the best flavor. Fresh thyme makes the casserole taste great.
• Don’t Rush the Onions: Cook the onions slowly until they are dark golden. This makes them sweet and tasty.
• Choose Quality Cheese: Good-quality Gruyère cheese melts well and adds a rich flavor.
• Layer Carefully: When putting the casserole together, make sure the bread is soaked in the onion mixture to keep it moist.
• Let It Rest: After baking, let the casserole sit for 10 minutes before serving. This helps it set and makes it easier to serve.

How To Store & Reheat Leftovers

• Refrigerate: First, let the leftover French Onion Chicken Casserole cool to room temperature. Then, put it in an airtight container and store it in the fridge for up to 3 days.
• Freeze: To freeze, let leftover French Onion Chicken Casserole cool completely, then put it in a freezer-safe container. It can be frozen for up to 3 months. To thaw, move it to the fridge overnight before reheating.
• Reheating: To reheat leftover French Onion Chicken Casserole, preheat the oven to 350°F (175°C) and cover with foil. Reheat for 5 minutes until heated through.

Nutrition Facts

Serving Size: 1 cup (approximately 240 grams)

• Calories: 390
• Total Fat: 22g
• Saturated Fat: 12g
• Cholesterol: 70mg
• Sodium: 850mg
• Potassium: 580mg
• Total Carbohydrate: 25g
• Dietary Fiber: 2g
• Sugars: 3g
• Protein: 25g

Try More Pioneer Woman Recipe:

• Pioneer Woman Chicken Piccata With Buttery Lemon Noodles
• Pioneer Woman Bourbon Chicken
• Pioneer Woman Fried Chicken Recipe
• Pioneer Woman Chicken Bacon Ranch Casserole
• Pioneer Woman Cheeseburger Casserole