By Gary 
French Onion Chicken Casserole Recipe
This comforting French Onion Chicken Casserole is perfect for any family gathering, delivering a savory blend of creamy goodness and crunchy textures. It’s a simple way to enjoy the classic flavors of French cuisine right from your own kitchen. Designed to serve a family of 5, this recipe provides hearty servings and can easily become a family favorite.
Ingredients (Serves a Family of 5):
Dairy & Fats:
– 1 1/4 tablespoons unsalted butter
– 3/4 cup sour cream
– 3/4 cup mayonnaise
– 1 1/2 cups Gruyere cheese, shredded (divided)
Vegetables & Herbs:
– 1 cup chopped yellow onion
– 1/3 cup chopped celery
– 1/3 cup chopped carrot
– 2 teaspoons finely chopped fresh garlic
– 1 1/2 teaspoons fresh thyme leaves (plus more for garnish)
Seasonings:
– 3/4 teaspoon kosher salt
– 3/4 teaspoon freshly ground black pepper (plus more for garnish)
Liquids:
– 3/4 (10.5 ounce) can condensed French onion soup
– 3 tablespoons dry white wine
Protein:
– 4 1/2 cups chopped rotisserie chicken (from approximately 1 and 1/8 whole rotisserie chickens)
Others:
– 3/4 teaspoon Dijon mustard
– 3.75 ounces seasoned croutons (approximately 3/4 of a 5-ounce package)
Step-by-Step Instructions:
Preparation
Gather all necessary ingredients and ensure everything is measured out for a smooth cooking experience. Preheat your oven to 350 degrees F (175 degrees C) to get ready for baking.
Cooking the Base
In a large skillet, melt the butter over medium heat. Add the chopped onion, celery, carrot, garlic, thyme, salt, and pepper. Cook and stir often until the onions soften and become translucent, taking about 5 to 7 minutes.
Creating the Sauce
Pour in the condensed French onion soup and white wine. Bring this mixture to a gentle simmer over medium heat, letting it reduce and thicken slightly, which should take about 2 to 3 minutes. Stir in the sour cream, mayonnaise, and Dijon mustard, returning to a simmer. Add 3/4 cup of the Gruyère cheese and cook, stirring continuously, until melted and silky, roughly 1 minute. Remove from the heat and fold the chopped rotisserie chicken into the sauce.
Assembly
Transfer the chicken-sauce mixture into a 9×13-inch baking dish. Evenly distribute the seasoned croutons over the mixture, then sprinkle the top with the remaining 3/4 cup of Gruyère cheese.
Baking
Place the dish into the preheated oven. Bake until the casserole is hot and bubbly, and the cheese has melted beautifully, which usually takes about 12 to 15 minutes.
Serving
Once baked, let the dish rest for around 10 minutes before serving to allow the flavors to meld and the casserole to set slightly. Garnish with extra thyme leaves and freshly ground black pepper to enhance the flavor and add a touch of elegance.
Conclusion:
Enjoy this delightful French Onion Chicken Casserole that’s sure to impress your family with its rich flavors and hearty texture. Whether it’s a regular weeknight dinner or a special occasion, this dish will offer warmth and satisfaction for everyone at the table.
Alex Harrington