French Onion Chicken Casserole

This French onion chicken casserole brings all the rich, savory flavors of the classic soup into a hearty and satisfying main course. It features tender chicken and egg noodles enveloped in a creamy onion sauce, all baked under a blanket of melted cheese and crispy onions.

Ready in under an hour, this dish is a straightforward and comforting option for a weeknight dinner. Most of the work happens in one skillet before the casserole goes into the oven, making cleanup manageable.

Why will you love French Onion Chicken Casserole?

Browning the chicken first develops a deeper, more savory flavor that spreads throughout the entire casserole.

Deglazing the pan with sherry after cooking the onions captures all the flavorful browned bits, creating a rich foundation for the sauce.

Adding the crispy fried onions at the end of the baking process ensures they stay crunchy and don’t get soggy in the oven.

French Onion Chicken Casserole Ingredients

• Chicken: Both chicken breasts and thighs work well in this recipe. Thighs will provide a slightly richer flavor and more moisture.

• Cheese: Gruyère is a classic choice for French onion soup and melts beautifully. If you can’t find it, a good quality sharp white cheddar or even Swiss cheese are great alternatives.

• Dry Sherry: This adds a characteristic tangy depth. If you need a substitute, use chicken broth, beef broth, or even white grape juice with a splash of vinegar.

• Cream of Mushroom Soup: This provides a convenient, creamy base. If you’re not a fan, cream of chicken or cream of celery soup will also work.

• Egg Noodles: Wide or extra-wide egg noodles are sturdy enough to hold up in the creamy sauce. You could also use another short, robust pasta like rotini or penne.

Exact quantities are in the recipe card below.

How to Make French Onion Chicken Casserole

Step 1: Prepare Noodles and Oven

First, get your oven preheating to 350°F and grease your baking dish. Boil a pot of water to cook the egg noodles until they are just al dente, then drain them well.

Step 2: Cook Chicken and Onions

In a large skillet, cook the seasoned chicken pieces in butter until they are browned. Add the sliced onion and cook it down, then pour in the sherry to deglaze the pan, letting it simmer and reduce.

Step 3: Mix the Casserole Base

In a large mixing bowl, stir together the sour cream, condensed soup, onion soup mix, and half of the shredded cheese. Add the cooked noodles and the chicken-onion mixture from the skillet, and mix until everything is coated in the creamy sauce.

Step 4: Bake in Two Stages

Transfer the mixture to your baking dish and top with the remaining cheese. Bake for 20 minutes. Finally, sprinkle the French fried onions on top and bake for 5-7 more minutes until everything is hot and the topping is golden.

What to Serve with French Onion Chicken Casserole

This rich casserole pairs well with something simple and fresh, like a crisp green salad with a vinaigrette or a side of steamed green beans.

Helpful Tricks for French Onion Chicken Casserole

Food Safety: For safe consumption, poultry should always be cooked to a minimum internal temperature of 165°F (74°C). Use a meat thermometer inserted into the thickest part of a chicken piece to verify.

Cheese Choice: While sharp white cheddar is great, using Gruyère cheese will give the casserole a flavor profile that is even closer to traditional French onion soup.

No Sherry: If you prefer not to cook with alcohol, you can substitute the dry sherry with an equal amount of chicken or beef broth.

Noodle Tip: Be careful not to overcook the egg noodles in the initial step. They will continue to cook in the oven, so boiling them just until al dente prevents them from becoming mushy.

How to Store and Freeze French Onion Chicken Casserole

Store leftovers in an airtight container in the refrigerator for up to 3 days. The casserole can be frozen before adding the crispy onion topping for up to 3 months. To reheat, place in an oven-safe dish and bake at 350°F (175°C) until warmed through, or reheat individual portions in the microwave.

French Onion Chicken Casserole Recipe FAQs

Can I make this casserole ahead of time?

Yes. You can assemble the entire casserole, without the cheese and fried onion toppings, up to a day in advance. Cover and refrigerate. When ready to bake, add about 10 minutes to the initial baking time.

Is there a non-alcoholic substitute for the sherry?

Absolutely. You can replace the dry sherry with an equal amount of chicken broth, beef broth, or even a non-alcoholic cooking wine. The flavor will be slightly different but still very good.

What can I use instead of canned cream of mushroom soup?

If you prefer to avoid canned soup, you can make a simple homemade cream sauce. Melt 3 tablespoons of butter in a saucepan, whisk in 3 tablespoons of flour, then slowly whisk in 1.5 cups of milk until thickened. Season with salt and pepper.

French Onion Chicken Casserole

Tender chicken and egg noodles are baked in a creamy sherry and onion sauce, topped with melted cheese and crispy fried onions.

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Prep Time 15 minutes mins

Cook Time 35 minutes mins

Total Time 50 minutes mins

Course Main Course

Cuisine American

Servings 8

Ingredients

  

• 12 oz wide egg noodles 340g
• 2 tbsp unsalted butter 28g
• 1.5 lbs boneless skinless chicken breasts or thighs, cut into 1-inch pieces, 680g
• 1 tsp dried thyme
• 1/2 tsp garlic powder
• 1/2 tsp salt
• 1/4 tsp black pepper
• 1 large yellow onion thinly sliced
• 1/3 cup dry sherry 80ml
• 1 can condensed cream of mushroom soup 10.5 oz / 298g
• 2 cups sour cream 450g
• 1 packet dry onion soup mix 1 oz / 28g
• 2 cups shredded sharp white cheddar or Gruyère cheese divided, 8 oz / 226g
• 1.5 cups French fried onions 105g

Instructions

 

• Preheat your oven to 350°F (175°C). Lightly grease a 9x13-inch baking dish. Cook egg noodles in a large pot of salted boiling water according to package directions for al dente. Drain and set aside.
• While the noodles cook, melt butter in a large skillet over medium-high heat. Add the chicken pieces and season with thyme, garlic powder, salt, and pepper. Cook, stirring occasionally, until browned on all sides, about 5-7 minutes.
• Reduce the heat to medium, add the sliced onion to the skillet, and cook until it begins to soften, about 4-5 minutes. Pour in the sherry, scraping up any browned bits from the bottom of the pan. Simmer until the liquid has mostly reduced.
• In a large bowl, combine the condensed soup, sour cream, dry onion soup mix, and 1 cup of the shredded cheese. Stir until smooth.
• Add the drained noodles and the chicken and onion mixture to the bowl with the sauce. Stir everything together until well combined.
• Pour the mixture into your prepared baking dish and spread it into an even layer. Sprinkle the remaining 1 cup of cheese over the top.
• Bake uncovered for 20 minutes, or until the sauce is bubbly and the cheese is melted.
• Remove the casserole from the oven and scatter the French fried onions evenly over the top. Return to the oven and bake for another 5-7 minutes, until the onions are golden brown. Ensure the chicken is cooked through by checking it has reached an internal temperature of 165°F (74°C). Let it rest for a few minutes before serving.

Notes

Food Safety: For safe consumption, poultry should always be cooked to a minimum internal temperature of 165°F (74°C). Use a meat thermometer inserted into the thickest part of a chicken piece to verify.

Cheese Choice: While sharp white cheddar is great, using Gruyère cheese will give the casserole a flavor profile that is even closer to traditional French onion soup.

No Sherry: If you prefer not to cook with alcohol, you can substitute the dry sherry with an equal amount of chicken or beef broth.

Noodle Tip: Be careful not to overcook the egg noodles in the initial step. They will continue to cook in the oven, so boiling them just until al dente prevents them from becoming mushy.

Keyword Casserole, Chicken, comfort food, french onion chicken casserole, Pasta