Mushroom Chicken Casserole – Creamy, Easy & Weight Watchers Friendly

If you love creamy, comforting casseroles but don’t want a dinner that feels overly heavy, this Mushroom Chicken Casserole is one you’ll want to add to your meal rotation.

This easy chicken casserole combines tender cooked chicken, savory mushrooms, spaghetti, and a creamy homemade sauce that’s full of flavor. Everything comes together in one skillet before being transferred to a casserole dish and baked until hot and bubbly with a lightly golden Parmesan topping.

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It’s classic comfort food with a lighter twist.

This Mushroom Chicken Casserole is also a great recipe to have on hand when you have leftover chicken in the refrigerator. Instead of serving the same chicken leftovers again, you can turn them into an entirely different meal the family will enjoy.

And if you’re following Weight Watchers, this is a great option when you’re looking for a comforting Weight Watchers chicken casserole that can fit into your meal plan.

Why You’ll Love This Mushroom Chicken Casserole

There are plenty of reasons this recipe has remained a favorite in my kitchen.

It’s easy to make!

Once your chicken and spaghetti are cooked, the rest of the recipe comes together quickly. The mushroom sauce is made right in a skillet, and then everything is combined and baked.

It’s a great way to use leftover chicken!

I love a recipe that helps prevent food waste. If you have leftover baked, grilled, or roasted chicken, this is an easy way to turn it into a completely new dinner.

It’s creamy without being too heavy!

Traditional creamy chicken casseroles can rely heavily on cream, butter, and cheese. This recipe takes a lighter approach by using fat-free chicken broth, skim milk, light butter, and flour to create the sauce.

It’s family-friendly!

The flavors in this Mushroom Chicken Casserole are simple and familiar. Tender chicken, pasta, mushrooms, Parmesan, and a creamy sauce make this a comforting meal that works well for the whole family.

It makes eight servings!

This recipe makes a generous 9×13-inch casserole that’s divided into eight servings, making it a great choice for family dinner or meal prep. Click here to see my favorite baking dish. 

Ingredients for Mushroom Chicken Casserole

You only need a handful of basic ingredients to make this easy chicken mushroom casserole.

Cooked Chicken Breast

You’ll need 2 cups of cooked, chopped chicken breast.

This is a perfect recipe for leftover chicken. You can use baked, grilled, or roasted chicken as long as it’s already cooked.

I prefer chicken breast because it’s lean and provides plenty of protein.

Mushrooms

I used baby bella mushrooms, but white button mushrooms work just as well.

You can use anywhere from 1 to 2 cups of sliced mushrooms depending on how much your family enjoys them. If you’re a mushroom lover, definitely go with the full 2 cups!

Light Butter

A small amount of light butter spread with canola oil is used to sauté the mushrooms and begin building the sauce.

Flour

All-purpose flour is used to thicken the mushroom sauce.

When the flour is combined with the melted butter and chicken broth, it creates a creamy sauce that coats the chicken and spaghetti.

Fat-Free Chicken Broth

The chicken broth is an important part of the sauce because it provides plenty of savory flavor without needing a heavy cream sauce.

For the recipe and nutritional information provided here, use fat-free chicken broth. Click here to see the exact broth I use. 

Skim Milk

A small amount of skim milk adds creaminess to the sauce while keeping the recipe lighter.

Seasonings

The sauce gets its flavor from a simple combination of:

• Garlic powder
• Onion powder
• Salt
• Black pepper
• Parsley
• Nutmeg

The nutmeg may seem like an unusual ingredient in a chicken casserole, but just a small amount adds a subtle depth of flavor to the creamy sauce.

White Cooking Wine

White cooking wine adds another layer of flavor to the sauce. If you don’t have it available, you can substitute water.

Spaghetti

You’ll need 4 ounces of spaghetti, which is half of a standard 8-ounce package.

You can break the spaghetti in half before cooking if you prefer shorter pieces that are easier to mix throughout the casserole. I love this brand of noodles. 

Parmesan Cheese

A small amount of shredded Parmesan cheese goes over the top of the casserole before baking. It adds a savory, cheesy finish and helps the top become lightly golden.

Ingredients for Mushroom Chicken Casserole

• 2 cups cooked, chopped chicken breast
• 1/8 cup light butter spread with canola oil
• 1–2 cups sliced mushrooms (I use baby bella mushrooms)
• 1/4 cup all-purpose flour
• 2 cups fat-free chicken broth
• 1/4 cup skim milk
• 1/2 teaspoon salt
• 1/2 teaspoon garlic powder
• 1/2 teaspoon onion powder
• 1/2 teaspoon chopped curly or Italian flat-leaf parsley
• 1/8 teaspoon nutmeg
• 1/4 teaspoon ground black pepper
• 1/8 cup white cooking wine
• 4 ounces spaghetti (1/2 of an 8-ounce package)
• 1/4 cup shredded Parmesan cheese

Substitution: If you don’t have white cooking wine, you can substitute water.

How to Make Mushroom Chicken Casserole

1. Preheat the Oven

Preheat your oven to 350°F.

Spray a 9×13-inch baking dish with nonstick cooking spray and set aside. Here’s the baking dish I love. 

2. Cook the Mushrooms

Place a large skillet over medium heat and melt the light butter.

Add the sliced mushrooms and cook for approximately 5 minutes, stirring occasionally, until the mushrooms are tender.

3. Make the Creamy Mushroom Sauce

Sprinkle the flour over the cooked mushrooms and melted butter.

Whisk everything together until the flour is incorporated.

Slowly add the fat-free chicken broth, whisking as you pour. Continue whisking until the flour, broth, butter, and mushrooms are thoroughly combined.

Turn up the heat slightly and continue stirring until the mixture comes to a boil.

Once it begins boiling, remove the skillet from the heat.

4. Add the Seasonings

Add the skim milk, salt, garlic powder, onion powder, parsley, nutmeg, black pepper, and white cooking wine.

Stir until everything is well combined.

You’ll now have a creamy, savory mushroom sauce that will coat the chicken and pasta.

5. Add the Chicken and Spaghetti

Add your cooked, chopped chicken breast to the skillet.

Next, add the cooked spaghetti.

Gently stir everything together until the chicken and spaghetti are evenly coated with the mushroom sauce.

6. Assemble the Casserole

Transfer the chicken and spaghetti mixture to the prepared 9×13-inch baking dish.

Spread it evenly.

Sprinkle the Parmesan cheese over the top.

7. Bake

Place the casserole in the oven and bake for 25–35 minutes, or until the casserole is bubbling and the edges are lightly golden.

8. Let It Rest

Remove the Mushroom Chicken Casserole from the oven and allow it to rest for approximately 5 minutes before serving.

This gives the sauce a chance to settle and makes the casserole easier to portion.

Cut into 8 equal servings.

Tips for Making the Best Mushroom Chicken Casserole

Use leftover chicken. This is one of the easiest ways to make this recipe. Keep cooked chicken in the refrigerator and you’ll have most of the main ingredient ready to go.

Don’t rush the mushrooms. Give the mushrooms enough time to become tender before adding the flour.

Whisk the sauce thoroughly. Whisking the flour and broth together helps create a smooth sauce and prevents floury lumps.

Don’t overbake it. The casserole is already cooked before it goes into the oven. You’re primarily heating everything through and allowing the flavors to come together. Once the edges are bubbling and the top is lightly golden, it’s ready.

Let it rest before cutting. Five minutes is enough to allow the casserole to settle slightly before serving. It’s even easier for meal prep if you let it cool completely in the refrigerator before cutting. 

Can I Use Rotisserie Chicken?

Absolutely!

Rotisserie chicken is a convenient shortcut for this chicken mushroom casserole. Simply remove the skin and bones, chop the chicken, and measure out 2 cups.

If you’re watching your calories or WW Points, keep in mind that using a different type of chicken can change the nutritional information.

Can I Use a Different Type of Pasta?

Yes. Spaghetti is what I use in this recipe, but other pasta shapes can work.

Penne, rotini, bowties, or another short pasta would all be good choices.

If you’re following Weight Watchers or tracking calories, keep the amount of pasta consistent with the recipe because changing the quantity will change the nutritional information and Points.

Can I Use Turkey Instead of Chicken?

Yes! This is a great recipe for leftover turkey, especially after Thanksgiving.

Simply replace the cooked chicken breast with an equal amount of cooked, chopped turkey.

The creamy mushroom sauce and Parmesan work beautifully with turkey.

What Can I Serve With Mushroom Chicken Casserole?

Because this casserole already contains chicken and pasta, you don’t need a lot of side dishes.

A simple vegetable or salad is all you really need to round out the meal.

Some good options include:

• Roasted broccoli
• Steamed carrots
• Roasted Brussels sprouts
• A simple green salad
• Cucumber salad
• Fresh fruit

I especially like serving a crisp vegetable or salad alongside this creamy casserole. The freshness balances out the richness of the sauce.

Can I Make This Mushroom Chicken Casserole Ahead of Time?

Yes, you can assemble the casserole ahead of time, cover it, and refrigerate it until you’re ready to bake.

Because the casserole will be cold when it goes into the oven, you may need to add additional baking time.

Be sure the center is heated through and the edges are bubbling before serving.

How to Store Leftover Mushroom Chicken Casserole:

Store leftovers in an airtight container in the refrigerator.

To reheat, place an individual serving in the microwave and heat until warmed through.

The sauce may thicken as it sits in the refrigerator. If you find that it needs loosening when reheating, add a small splash of milk or chicken broth.

Is Mushroom Chicken Casserole Good for Meal Prep?

Yes! Since this recipe makes eight servings, it’s a convenient option for meal prep.

You can portion the casserole into individual containers after it has cooled and refrigerate the portions for easy lunches or dinners throughout the week.

This is also one of those recipes that makes leftovers you won’t mind eating again.

Check out my favorite meal prep containers here. 

Weight Watchers Mushroom Chicken Casserole

If you’re looking for Weight Watchers recipes that don’t feel like you’re missing out on your favorite comfort foods, this casserole is a great choice.

The combination of chicken, mushrooms, spaghetti, and a creamy homemade sauce makes this feel like a traditional comfort-food casserole while using lighter ingredients.

The Points information for this recipe is 5 Points per serving. 

Frequently Asked Questions

Can I use canned mushrooms?

Fresh mushrooms are my preference for this recipe, but canned mushrooms can work in a pinch. Drain them well before adding them to the skillet.

Keep in mind that the texture will be different from fresh mushrooms.

Can I make mushroom chicken casserole without wine?

Yes. If you don’t have white cooking wine, you can substitute water as listed in the original recipe.

How many servings does this recipe make?

This recipe makes 8 servings. Each serving is one-eighth of the finished casserole.

Is this a Weight Watchers mushroom chicken casserole?

Yes. This recipe was originally created as a lighter casserole and includes the original Weight Watchers Points information. Always check the current WW app for the most accurate Points value based on your ingredients.

More Easy Chicken Recipes

If you’re looking for more easy, family-friendly chicken dinners, be sure to check out some of my other recipes. Chicken is one of my favorite ingredients because it’s versatile, affordable, and easy to turn into a satisfying family meal.

Final Thoughts

There’s something so comforting about a bubbling casserole coming out of the oven, and this Mushroom Chicken Casserole is exactly that kind of meal.

The tender chicken, mushrooms, spaghetti, creamy sauce, and Parmesan topping come together to make a dinner that feels indulgent without being overly heavy.

It’s also practical. You can use leftover chicken, the recipe makes eight servings, and most of the preparation can be done in one skillet before everything goes into the oven.

Whether you’re looking for an easy weeknight dinner, a way to use leftover chicken, or a lighter comfort-food recipe, this Mushroom Chicken Casserole is a recipe worth keeping.