Name: Creamy Chicken Mushroom Casserole Recipe
Prep time: 30 min
Cook time: 45 min
Total time: 1 h 15 min
Cuisine: American
Ingredients: 2 1/2 lbs chicken breasts (4 to 5 large), cut into 1-inch thick strips; 1 1/2 tsp sea salt (plus more to taste); 1/4 tsp black pepper (plus more to taste); 1 cup all-purpose flour (to coat the chicken); 6 Tbsp olive oil (divided); 1 lb white mushrooms, thickly sliced; 1 medium onion, finely diced; 3 garlic cloves, minced; 3 Tbsp unsalted butter; 3 Tbsp all-purpose flour (for the sauce); 1 1/2 cups chicken broth; 1 Tbsp lemon juice; 1 cup half and half (or 1/2 cup milk + 1/2 cup heavy cream)

If you’re craving a cozy, irresistibly comforting dish that everyone will ask for seconds of, you’re in the right place. This Creamy Chicken Mushroom Casserole Recipe is one of my all-time favorites—rich, tender chicken paired with earthy mushrooms in a luscious creamy sauce that’s just pure magic. Once you make this, I promise you’ll want to keep it in your regular dinner rotation.

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Why You’ll Love This Recipe

Perfectly tender chicken: The chicken stays juicy and melts in your mouth every single time, thanks to the careful flour dredging and oven finish.
Rich, creamy sauce: Combining butter, flour, chicken broth, and half-and-half creates a dreamy sauce that’s comforting without being heavy.
Mushrooms and onions add depth: Sautéed until golden, they give the casserole an earthy flavor that balances perfectly with the creamy sauce.
Makes great leftovers: This casserole reheats beautifully, so you can enjoy it again with minimal effort.

A white rectangular baking dish filled with a creamy mushroom sauce containing cooked light brown chicken pieces scattered throughout. The sauce is thick and light beige with visible slices of sautéed mushrooms mixed in. Fresh green parsley leaves are placed on top as garnish in several spots. The dish is placed on a white marbled surface. A copper spoon and a woman's hand holding the dish are partially visible on the right side. Photo taken with an iphone --ar 4:5 --v 7

Ingredients You’ll Need

Each ingredient in this Creamy Chicken Mushroom Casserole Recipe plays a key role in building layers of flavor and texture—you’ll see how simple ingredients can come together to wow your taste buds. Plus, these are pantry-friendly staples with a fresh touch.

Chicken breasts: I prefer skinless, boneless large breasts, cut into thick strips so they cook evenly and stay juicy.
Sea salt and black pepper: Seasoning is everything here; don’t be shy with salt to bring out the flavors.
All-purpose flour: Used twice—first to coat the chicken for a nice golden crust, then for thickening the creamy sauce.
Olive oil: Choose good quality for sautéing the chicken and veggies; it adds subtle richness.
White mushrooms: Slice them thick for a meaty texture and deep flavor in the sauce.
Onion: A medium onion finely diced adds sweetness and body when sautéed.
Garlic cloves: Minced fresh garlic gives that punch of savory aroma you can’t skip.
Unsalted butter: For richness in the sauce without overpowering saltiness.
Chicken broth: Use low sodium if possible, so you control the saltiness; it enriches the sauce’s flavor.
Lemon juice: This little zing brightens up the creamy sauce—you’ll notice the fresh lift it adds.
Half and half (or milk plus heavy cream): The star of creaminess here; I’ve successfully swapped half and half with a milk and cream combo for perfect balance.

Note: You’ll find the complete list of ingredients, along with their exact measurements, in the printable recipe card at the bottom of this post.

Variations

I love that this Creamy Chicken Mushroom Casserole Recipe is so adaptable—you can easily tweak it to fit your mood or occasion. Here’s how I like to mix things up depending on what’s in my kitchen or my family’s cravings.

Mushroom Mix: Sometimes, I swap white mushrooms for baby bella or cremini for a deeper flavor profile that’s a bit earthier.
Added Veggies: Feel free to throw in some spinach or peas in the last few minutes of baking for a pop of green and freshness.
Dairy Alternatives: If you want a lighter casserole, using milk and a splash of cream works just as well as half and half, keeping the sauce silky but with fewer calories.
Herbs: I’ve tried stirring in fresh thyme or rosemary for a fragrant boost—your choice depending on what you like!

How to Make Creamy Chicken Mushroom Casserole Recipe

Step 1: Season and Sauté Your Chicken

Start by seasoning your chicken strips with sea salt and black pepper—this step really builds the foundational flavor. Then, coat each piece in all-purpose flour; it might seem old-fashioned, but it locks in moisture and ensures the outside crisps up beautifully. Heat half of your olive oil over medium-high heat in a large skillet. When the oil shimmers, add the chicken in batches—don’t crowd the pan or the pieces will steam instead of sear. Give each side about 3-4 minutes until golden brown. Don’t fret if they’re not cooked through yet; we’ll finish them in the oven. Once golden, transfer them to your casserole dish.

Step 2: Sauté Mushrooms, Onions, and Garlic

Wipe your skillet clean or just scrape off any bits stuck to the bottom, then add the remaining oil. Toss in the thick-sliced mushrooms and diced onions. Sauté them together until they soften and turn golden—this usually takes about 7-8 minutes. When that lovely caramelization hits, add the minced garlic and cook for another minute or two. Spread this golden mushroom-onion mix evenly over the chicken in your baking dish, layering flavor as you go.

Step 3: Whisk Up the Creamy Sauce

In the same skillet or a separate saucepan, melt the butter over medium heat. Stir in the flour and whisk constantly until it turns a light golden color, around 1-2 minutes—this roux is what thickens your sauce into that perfect velvety texture. Slowly pour in the chicken broth while whisking aggressively to avoid lumps. Add the lemon juice and a pinch of black pepper, then gradually stir in the half and half. Bring the sauce to a gentle simmer and keep whisking until it thickens nicely. Taste and adjust seasoning with salt and pepper—this is where you really build that creamy, zesty balance.

Step 4: Bake Until Bubbly and Perfect

Pour the luscious sauce evenly over the layered chicken and mushrooms. Cover your casserole with foil (this keeps the chicken moist) and place it in the oven preheated to 350˚F. Bake for 45 minutes, then take off the foil and bake another 5-10 minutes if you want a lightly browned top. When done, the chicken will be tender and the flavors deeply melded—a true comfort food winner.

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Pro Tips for Making Creamy Chicken Mushroom Casserole Recipe

Patience with the Sear: Take your time browning the chicken; it’s this step that adds so much flavor and texture later on.
Don’t Skip the Roux’s Golden Stage: Watch the flour and butter mixture carefully—it should be just golden, never burnt, for the best sauce base.
Use Fresh Lemon Juice: It brightens the sauce in a way that bottled lemon juice can’t match, trust me on this one.
Cover During Baking: Keeping the casserole covered prevents drying out and helps all flavors mingle perfectly.

How to Serve Creamy Chicken Mushroom Casserole Recipe

A white rectangular dish filled with creamy chicken and mushroom sauce. The dish has several pieces of light brown cooked chicken partly covered by thick, creamy white sauce with slices of soft, cooked mushrooms scattered on top. Bright green parsley leaves are sprinkled over the sauce for color contrast. A wooden spoon with the tip in the sauce rests on the right side of the dish. The background is a white marbled surface. Photo taken with an iphone --ar 4:5 --v 7

Garnishes

I like to sprinkle fresh chopped parsley or thyme on top just before serving to add a burst of color and a fresh herbal hint that cuts through the creaminess beautifully. A little cracked black pepper on top looks great and adds a subtle kick, too.

Side Dishes

This casserole pairs beautifully with buttery mashed potatoes (classic combo!), creamy polenta, or buttered egg noodles. For lighter options, steamed green beans or a crisp side salad refresh the palate and balance the richness.

Creative Ways to Present

For a dinner party, I’ve served this casserole in individual ramekins with a small mushroom and herb bouquet on top. It feels extra special and lets everyone enjoy their personal portion. You could also try layering it in a trifle dish for a ‘deconstructed’ look if you’re into fun plating.

Make Ahead and Storage

Storing Leftovers

I store leftovers in an airtight container in the fridge for up to 3 days. This casserole actually tastes better the next day once the flavors have had time to meld, so I’m always happy to have some waiting in the fridge!

Freezing

Freezing works well too—just cool completely then cover tightly with foil and plastic wrap or use a freezer-safe container. When you’re ready, thaw overnight in the fridge before reheating for best texture.

Reheating

To reheat, I cover the casserole with foil and warm it in a 350˚F oven until heated through, about 20 minutes. This keeps the chicken moist and sauce creamy without drying out or losing that fresh-from-the-oven taste.

FAQs

Can I use chicken thighs instead of breasts in this casserole?

Absolutely! Boneless, skinless chicken thighs work great and bring extra juiciness and flavor. Just adjust the cooking time slightly to ensure they’re cooked through, as thighs can be thicker and fattier.
What can I substitute if I don’t have half and half?

If half and half isn’t on your shelf, mixing equal parts of milk and heavy cream is a perfect substitute that maintains the sauce’s richness and creaminess.
Can I prepare this casserole ahead of time?

Yes! You can assemble the casserole a day in advance, cover it tightly, and keep it refrigerated. When ready, bake it as directed, adding a few extra minutes if baking straight from the fridge.
Is this casserole gluten-free?

This recipe uses all-purpose flour for coating and sauce thickening, which contains gluten. To make it gluten-free, try substituting with gluten-free flour blends and ensure your broth is gluten-free.

Final Thoughts

Honestly, this Creamy Chicken Mushroom Casserole Recipe holds a special place in my heart—not just because it’s delicious, but because it’s the kind of comforting meal that brings everyone to the table, smiles, and seconds. Every time I make it, I’m reminded that good food doesn’t have to be complicated to be incredible. So grab your skillet, invite some mushrooms and chicken to party together, and give this recipe a whirl—you’ll love how it comes together and tastes just like a warm hug on a plate.