Cheesy Chicken French Onion Casserole
A comforting and flavorful casserole combining tender chicken, caramelized onions, creamy cheese sauce, and crispy French fried onions for a deliciously cheesy and savory meal.
- Prep Time: 20 minutes
- Cook Time: 45 minutes
- Total Time: 1 hour 5 minutes
- Yield: 6
Ingredients
2 tablespoons unsalted butter
3 large yellow onions, thinly sliced
1 teaspoon salt
1/2 teaspoon black pepper
1/2 teaspoon dried thyme
3 cups cooked chicken, shredded or diced
2 tablespoons all-purpose flour
1 1/2 cups whole milk
1/2 cup sour cream
1 cup shredded sharp cheddar cheese
1 cup shredded Gruyère cheese
1/2 cup grated Parmesan cheese
1 1/2 cups French fried onions (store-bought)
1/4 cup chopped fresh parsley (for garnish)
Instructions
Preheat the oven to 350°F (175°C).
In a large skillet, melt the butter over medium heat.
Add the sliced onions, salt, black pepper, and dried thyme to the skillet.
Cook the onions, stirring frequently, until they are deeply caramelized and golden brown, about 20 minutes.
Sprinkle the flour over the caramelized onions and stir well to combine. Cook for 2 minutes to remove the raw flour taste.
Gradually whisk in the milk and continue to cook, stirring constantly, until the sauce thickens, about 5 minutes.
Remove the skillet from heat and stir in the sour cream, shredded cheddar cheese, shredded Gruyère cheese, and grated Parmesan cheese until melted and smooth.
Add the cooked chicken to the cheese sauce and stir to combine.
Transfer the mixture to a greased 9×13-inch baking dish and spread evenly.
Sprinkle the French fried onions evenly over the top of the casserole.
Bake in the preheated oven for 20-25 minutes, or until the casserole is bubbly and the onions are golden brown.
Remove from the oven and let it rest for 5 minutes before serving.
Garnish with chopped fresh parsley and serve warm.