Description
This French Onion Chicken & Rice Casserole is a comforting, savory dish combining tender caramelized onions, juicy chicken, and fluffy rice baked to perfection with a golden Gruyère cheese topping. Ideal for a hearty family meal, it blends rich French onion flavors with wholesome ingredients for an easy, satisfying casserole.
Ingredients
Scale
Onions and Flavor Base
- 4 tbsp unsalted butter
- 2 tbsp olive oil
- 2 large sweet onions, thinly sliced
- 1 tsp salt, divided
- 1/2 tsp black pepper, divided
- 1 tbsp all-purpose flour
- 1/2 cup dry white wine
Main Ingredients
- 1 cup uncooked long-grain white rice
- 2 cups chicken stock
- 2 cups cooked chicken, shredded or diced
- 1 cup fresh baby spinach
- 1 cup sliced mushrooms
- 1/2 tsp dried thyme
- 1/4 tsp garlic powder
Topping
- 1 cup shredded Gruyère cheese
Instructions
- Preheat the oven: Set your oven to 350°F (175°C) to prepare for baking the casserole.
- Caramelize the onions: In a large skillet over medium heat, melt the butter with olive oil. Add the thinly sliced onions and cook for 25–30 minutes, stirring occasionally, until they are deeply caramelized and golden brown. Season them with 1/2 teaspoon salt and 1/4 teaspoon black pepper.
- Thicken the mixture: Sprinkle the flour over the onions and stir continuously for 1 minute to cook out the raw flour taste. Pour in the white wine, scraping up any browned bits from the skillet. Let the wine reduce for 2–3 minutes to concentrate the flavor.
- Assemble the casserole: In a 9×13-inch baking dish, combine the uncooked long-grain white rice, chicken stock, shredded or diced cooked chicken, fresh baby spinach, sliced mushrooms, dried thyme, garlic powder, and the remaining 1/2 teaspoon salt and 1/4 teaspoon black pepper. Stir everything together evenly.
- Layer the onions: Spread the caramelized onion mixture evenly over the rice and chicken mixture in the baking dish. Cover the dish tightly with aluminum foil to trap steam for even cooking.
- Bake: Place the covered casserole in the preheated oven and bake for 35 minutes. Then carefully remove the foil, sprinkle the shredded Gruyère cheese on top, and bake uncovered for an additional 10–15 minutes until the cheese is bubbly and golden brown.
- Rest and serve: Once baked, let the casserole rest for 5 minutes to set slightly before serving warm for best flavor and texture.
Notes
- For best caramelization, cook onions slowly over medium heat, stirring occasionally to prevent burning.
- Use cooked chicken from a rotisserie or leftover chicken to save prep time.
- If you prefer a richer flavor, swap chicken stock with bone broth.
- Gruyère cheese can be substituted with Swiss or mozzarella if unavailable.
- This casserole can be prepared a day ahead; store covered in the refrigerator and bake fresh before serving.
