French Onion Chicken Casserole

5.0
(1)
1 Review
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This French onion chicken casserole is creamy, rich, and aromatic. It has all the components of French onion soup—plus chicken—even a crisp crouton topping.

By
Craig Ruff
Headshot of Craig Ruff
Craig Ruff
Craig Ruff is a dedicated cook and lover of food science. His culinary background comes from culinary school and his time working in restaurants.
Allrecipes' editorial guidelines
Published on July 24, 2024
Tested by
Catherine Jessee
Catherine Jessee
Tested by Catherine Jessee
Catherine Jessee is a Test Kitchen Assistant in the Dotdash Meredith Food Studios. She has tested recipes for brands including Allrecipes, Eating Well, Food & Wine, Real Simple, People, and Southern Living. Prior to joining the Food Studios, she accumulated 3 years of experience cooking in restaurants. She has contributed to publications like Domino Magazine, The Knot Magazine, and Wildsam Almanacs. Her go-to potluck dish is Ritz Crackers and pimento cheese—always using her mom's recipe. You can follow her cooking adventures on Instagram @catherinejessee.
Meet the Allrecipes Test Kitchen
French Onion Chicken Casserole on a plate with a fork
Prep Time:
15 mins
Cook Time:
35 mins
Rest Time:
10 mins
Total Time:
1 hr
Servings:
8
Jump to Nutrition Facts

Ingredients

  • 2 tablespoons unsalted butter

  • 1 1/2 cups chopped yellow onion

  • 1/2 cup chopped celery

  • 1/2 cup chopped carrot

  • 1 tablespoon finely chopped fresh garlic

  • 2 teaspoons fresh thyme leaves, plus more for garnish

  • 1 teaspoon kosher salt

  • 1 teaspoon freshly ground black pepper, plus more for garnish

  • 1 (10.5 ounce) can condensed French onion soup

  • 1/4 cup dry white wine

  • 1 cup sour cream

  • 1 cup mayonnaise

  • 1 teaspoon Dijon mustard

  • 2 cups Gruyere cheese, shredded, divided

  • 6 cups chopped rotisserie chicken (from 1 1/2 whole rotisserie chickens)

  • 1 (5 ounce) package seasoned croutons

Directions

  1. Gather all ingredients. Preheat the oven to 350 degrees F (175 degrees C).

    French Onion Chicken Casserole ingredients in glass bowls

    Dotdash Meredith Food Studios

  2. Melt butter in a large skillet over medium heat. Add onion, celery, carrot, garlic, thyme, salt, and pepper; cook, stirring often, until onions are softened and translucent, 5 to 7 minutes.

    Onions, carrots and celery in a pan on a burner, with a wooden spoon

    Dotdash Meredith Food Studios

  3. Add French onion soup and wine, and bring to a simmer over medium heat. Simmer, undisturbed, until reduced and slightly thickened, 2 to 3 minutes. Stir in sour cream, mayonnaise, and mustard, and return to a simmer. Add 1 cup Gruyère, and cook, stirring constantly, until completely melted and combined, about 1 minute. Remove from heat, and fold in chicken.

    French Onion Chicken Casserole filling in a pan, stirred with a wooden spoon

    Dotdash Meredith Food Studios

  4. Transfer to a 9x13-inch baking dish. Sprinkle croutons evenly over chicken mixture; sprinkle evenly with remaining Gruyère cheese. Bake in the preheated oven until bubbling and cheese is melted, 12 to 15 minutes. Let rest 10 minutes before serving. Garnish with additional thyme and pepper.

    French Onion Chicken Casserole in a casserole pan

    Dotdash Meredith Food Studios

Nutrition Facts (per serving)

621 Calories
48g Fat
23g Carbs
22g Protein
Nutrition Facts
Servings Per Recipe 8
Calories 621
% Daily Value *
Total Fat 48g 62%
Saturated Fat 16g 82%
Cholesterol 109mg 36%
Sodium 947mg 41%
Total Carbohydrate 23g 8%
Dietary Fiber 2g 8%
Total Sugars 5g
Protein 22g 45%
Vitamin C 5mg 5%
Calcium 407mg 31%
Iron 2mg 9%
Potassium 366mg 8%

* Percent Daily Values are based on a 2,000 calorie diet. Your daily values may be higher or lower depending on your calorie needs.

** Nutrient information is not available for all ingredients. Amount is based on available nutrient data.

(-) Information is not currently available for this nutrient. If you are following a medically restrictive diet, please consult your doctor or registered dietitian before preparing this recipe for personal consumption.

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