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 comfort dish that feels like a warm hug on a plate, you’ve got to try my Creamy Chicken Mushroom Casserole Recipe. I absolutely love how this recipe brings tender chicken and luscious mushrooms together in a rich, velvety sauce. When I first tried this, it quickly became a family favorite because it’s surprisingly simple but delivers such deep flavor. Stick with me — I’ll walk you through every detail so you can nail it perfectly!

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Why You’ll Love This Recipe

Incredible Creamy Texture: The half-and-half sauce thickens perfectly for that dreamy consistency you want in a casserole.
Super Tender Chicken: Coating and searing the chicken creates a golden exterior but leaves it juicy and tender after baking.
Loaded with Flavor: Garlic, onion, mushrooms, and a splash of lemon juice add layers of rich, balanced taste.
Comfort Food Made Easy: Despite feeling fancy, this recipe is straightforward and uses ingredients you probably already have.

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

The magic of this Creamy Chicken Mushroom Casserole Recipe comes from simple, fresh ingredients that come together so beautifully. When shopping, I always make sure to get firm chicken breasts for the best texture and fresh white mushrooms for that earthy flavor.

Chicken breasts: Look for large, even pieces so they cook evenly; cutting them into strips gives great bite-sized portions.
Sea salt: Enhances flavors naturally without any bitterness.
Black pepper: Freshly ground if possible for that subtle spicy kick.
All-purpose flour: Used twice – first for coating the chicken and again for thickening the sauce.
Olive oil: Divided for searing chicken and sautéing veggies; adds a healthy richness.
White mushrooms: Choose firm and plump ones; they reduce down to a flavorful base in the casserole.
Onion: Finely diced to melt into the sauce and bring gentle sweetness.
Garlic cloves: Minced for that unmistakable aromatic depth.
Unsalted butter: Helps build the velvety roux for the sauce.
Chicken broth: Use a good-quality broth for the best taste.
Lemon juice: Just a splash brightens and balances the creamy sauce beautifully.
Half and half: Or sub with a blend of milk and heavy cream if preferred, for richness and creaminess.

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 customizing this casserole depending on what I have on hand or my mood. Feel free to experiment — the base is so forgiving you’ll find it easy to make your own!

Use different mushrooms: I once swapped white mushrooms for cremini and loved the deeper flavor they added.
Swap on the cream: When I wanted a lighter version, I used just milk and it still turned out delicious.
Add herbs: Thyme or rosemary folded into the sauce bring a lovely aromatic touch that you might enjoy.
Make it gluten-free: Use a gluten-free flour blend for coating and sauce to suit dietary needs without sacrificing texture.

How to Make Creamy Chicken Mushroom Casserole Recipe

Step 1: Season and Dredge the Chicken

The first thing I do is season my chicken strips really well with sea salt and black pepper. Then, I coat each piece in all-purpose flour, shaking off the excess. This step is key because it helps create that golden crust and later thickens the sauce a bit when we bake it. Make sure not to overcrowd your dredging bowl or else the coating gets soggy.

Step 2: Sear the Chicken

Heat half your olive oil in a large skillet over medium-high heat until it’s shimmering. Carefully add your chicken strips in a single layer, working in batches if needed. You want a nice golden sear on each side — it only takes a few minutes. Don’t fret about cooking them through; they’ll finish in the oven and stay tender this way. Once seared, transfer the chicken to your casserole dish.

Step 3: Sauté Mushrooms, Onions, and Garlic

In the same skillet, add the remaining olive oil. Toss in your sliced mushrooms and diced onion, letting them cook down until they’re soft and golden—this step brings out their natural sweetness and depth. Minutes before they’re done, stir in the minced garlic and cook for just about a minute or two to keep it fragrant but not burnt. Then spread this savory mixture evenly over the chicken in your casserole dish.

Step 4: Make the Creamy Sauce

Now for the sauce — melt the butter in a saucepan or the same skillet you just used. Sprinkle in the flour and whisk constantly for a minute or two until it turns light golden—this is your roux, the secret to that smooth sauce. Next, gradually pour in the chicken broth while whisking to avoid lumps. Add the lemon juice and a pinch of black pepper, stirring until everything’s silky. Stir in the half and half and bring it to a gentle simmer. Don’t forget to taste and season with salt and pepper — this sauce should sing with flavor!

Step 5: Bake and Serve

Pour your creamy sauce over the chicken and mushroom layers, cover the casserole dish tightly with foil, and bake at 350°F (175°C) for 45 minutes. Baking allows the flavors to meld beautifully while keeping the chicken unbelievably tender. When ready, serve it up warm — my favorite way is over fluffy mashed potatoes, but pasta or rice works just as well.

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Pro Tips for Making Creamy Chicken Mushroom Casserole Recipe

Don’t Skip Searing: It locks in moisture and adds a delicious texture to the chicken that baking alone won’t provide.
Use Fresh Mushrooms: They shrink but pack so much flavor; avoid pre-sliced from the deli to keep the texture intact.
Whisk Roux Constantly: This prevents lumps and keeps your sauce smooth and silky every time.
Cover While Baking: Keeps the chicken moist and stops the sauce from drying out on top.

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 often sprinkle chopped fresh parsley or chives on top just before serving — it adds a pop of color and a fresh brightness that contrasts the creamy sauce beautifully. Sometimes, a little extra cracked black pepper right on top is all the garnish this meal needs.

Side Dishes

This casserole pairs wonderfully with creamy mashed potatoes, buttered egg noodles, or even a simple rice pilaf. For veggies, I like to keep it light with steamed green beans or a crisp mixed green salad for balance.

Creative Ways to Present

For a dinner party, I’ve served this casserole in individual ramekins topped with a little parmesan crisp – it looks fancy but stays cozy and comforting. Another fun idea I tried was layering it with sautéed spinach under the mushrooms for an extra veggie punch and pop of color.

Make Ahead and Storage

Storing Leftovers

Once cooled, I tightly cover the casserole dish and refrigerate leftovers for up to 3 days. I find that the flavors actually deepen after resting overnight, making for an even tastier meal the next day.

Freezing

This Creamy Chicken Mushroom Casserole Recipe freezes beautifully. I portion it into airtight containers and freeze for up to 3 months. When you’re ready, thaw overnight in the fridge before reheating.

Reheating

I prefer reheating in the oven at 325°F (160°C) covered with foil to prevent drying out. It usually takes 20-25 minutes. The sauce stays creamy, and the chicken remains juicy without turning rubbery like microwaving can sometimes cause.

FAQs

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

Absolutely! Chicken thighs will add a bit more richness and stay even juicier thanks to the higher fat content. Just be sure to cut them into similar-sized pieces for even cooking.
What can I substitute if I don’t have half and half?

If you don’t have half and half, you can mix equal parts milk and heavy cream to create a similar richness. Whole milk alone will work, too, but the sauce won’t be quite as creamy.
Can I prepare this casserole ahead of time?

Yes! You can fully assemble the casserole a day ahead, keep it covered in the fridge, and bake it when you’re ready. Just add a few extra minutes to the baking time if it’s coming straight from cold.
Is this recipe gluten-free?

The traditional recipe uses all-purpose flour, which contains gluten. To make it gluten-free, use a gluten-free flour blend for coating and thickening or try cornstarch for the sauce.
What sides go best with this creamy chicken casserole?

Mashed potatoes, buttered noodles, or rice are all great choices. For veggies, steamed green beans, roasted carrots, or a fresh salad complement the richness of the casserole.

Final Thoughts

This Creamy Chicken Mushroom Casserole Recipe really feels like a special treat — it’s one of those meals that brings everyone to the table with big smiles. I love how adaptable it is and how it warms you up from the inside out. Give this recipe a try this weekend, and I promise it’ll become one of your go-to comfort dinners that you pull out time and time again.