There’s nothing quite like the smell of a creamy chicken and mushroom casserole bubbling away in the oven.
This dish has become a go-to in my home for busy weeknights, chilly weekends, or anytime I need to bring something hearty and homemade to the table.
It’s cozy, simple, and satisfying—packed with tender chicken, buttery mushrooms, and a silky, savory sauce that ties everything together.
This chicken and mushroom casserole is comfort food done right.
Why You’ll Love This Recipe
Rich and creamy sauce made from scratch
Perfect for weeknights or weekend meal prep
Uses everyday ingredients—no canned soups!
Family-friendly, freezer-friendly, and potluck-perfect
Bakes beautifully in under an hour
What You’ll Need (Ingredient Highlights)
Boneless, skinless chicken breasts – tender and juicy
Fresh mushrooms – bring earthy depth
Onion & garlic – aromatic foundation
Unsalted butter & flour – creates the creamy base
Chicken broth & half-and-half – build the luscious sauce
Lemon juice – adds brightness
Salt & black pepper – simple and classic seasoning
Pro Tips Before You Start
Slice chicken evenly for consistent cooking
Sauté mushrooms separately to bring out their flavor
Don’t rush the roux—let the flour cook out for a smooth sauce
Taste and adjust seasoning before baking
Let casserole rest a few minutes after baking for best texture
How to Make Chicken and Mushroom Casserole
Step 1: Preheat & Prepare
Preheat your oven to 350°F (175°C).
Lightly grease a 9×13 inch casserole dish and set it aside.
Step 2: Cook the Chicken
Slice chicken breasts into cutlets or thin strips.
In a large skillet over medium heat, melt some butter and cook the chicken until lightly golden on both sides, about 3–4 minutes per side.
Remove from skillet and set aside.
Step 3: Sauté the Vegetables
In the same skillet, add a bit more butter if needed.
Sauté the sliced mushrooms for 4–5 minutes until golden.
Add the chopped onion and cook for another 2–3 minutes until softened.
Stir in the minced garlic and cook until fragrant, about 30 seconds.
Step 4: Make the Sauce
Sprinkle flour over the mushroom mixture and stir well to coat.
Cook for 1 minute. Slowly whisk in chicken broth, followed by the half-and-half and lemon juice.
Stir constantly until the sauce is thickened and smooth, about 3–5 minutes.
Step 5: Assemble the Casserole
Arrange the cooked chicken in the prepared casserole dish.
Pour the mushroom sauce evenly over the top, making sure the chicken is fully covered.
Step 6: Bake
Cover the dish with foil and bake for 30 minutes.
Then uncover and bake for an additional 15 minutes, until the top is slightly golden and bubbly.
Step 7: Rest & Serve
Let the casserole rest for 5–10 minutes before serving.
This helps the sauce settle and makes serving easier.
What to Serve It With
Mashed potatoes, rice, or egg noodles
Steamed green beans, roasted broccoli, or carrots
A fresh garden salad with vinaigrette
Warm dinner rolls or garlic bread
A crisp glass of white wine or sparkling water with lemon
Variations / Substitutions
Use chicken thighs for more flavor
Swap half-and-half for heavy cream or milk (adjust thickness)
Add spinach or peas to the sauce for extra veggies
Use thyme, rosemary, or Italian seasoning for more depth
Make it cheesy by adding shredded mozzarella or parmesan on top before baking
Storage & Leftovers
Refrigerate leftovers in an airtight container for up to 4 days
Reheat in the oven at 325°F or microwave until heated through
Freeze unbaked or baked casserole (cooled) for up to 2 months
Thaw overnight in fridge before baking or reheating
Great for meal prep—store in individual containers
FAQs
Can I use pre-cooked or rotisserie chicken?
Yes! Just skip the browning step and add the shredded chicken directly to the casserole before baking.
Can I make this dish ahead of time?
Absolutely. Assemble the casserole and refrigerate up to 24 hours before baking.
Let sit at room temp 20 minutes before baking.
What type of mushrooms work best?
White button or cremini mushrooms are great.
You can also mix in shiitake or portobello for extra flavor.
Can I make it dairy-free?
You can substitute olive oil for butter and use a dairy-free milk alternative, but the flavor and texture may change slightly.
How do I thicken my sauce if it’s too runny?
Make a quick slurry with 1 tbsp flour + 2 tbsp water and stir it into the sauce over low heat until thickened.
What if I don’t have half-and-half?
You can mix equal parts milk and heavy cream as a substitute for half-and-half.
Final Thoughts
This chicken and mushroom casserole is one of those dishes that feels like a warm hug in a baking dish.
It’s easy to prepare, satisfying to serve, and always disappears quickly at the dinner table.
If you’re looking for a cozy classic that still feels special, this is the recipe to save.
Full Recipe Card (Ingredients + Instructions)
Ingredients
1½ lbs boneless, skinless chicken breasts
1 tbsp unsalted butter (for chicken)
1 tbsp unsalted butter (for vegetables)
8 oz mushrooms, sliced
1 small yellow onion, chopped
2 cloves garlic, minced
2 tbsp all-purpose flour
1 cup chicken broth
1 cup half-and-half
1 tbsp lemon juice
¾ tsp salt (or to taste)
½ tsp black pepper
Instructions
Preheat oven to 350°F. Grease a 9×13” baking dish.
Slice and brown chicken in butter until lightly golden. Set aside.
Sauté mushrooms in butter.
Add onion and cook until soft. Add garlic.
Stir in flour and cook 1 minute.
Whisk in broth, half-and-half, and lemon juice.
Simmer until thickened. Season with salt and pepper.
Layer chicken in baking dish. Pour sauce over.
Cover and bake 30 min. Uncover and bake 15 min more.
Rest 5–10 minutes before serving.
