Garlic Mushroom Chicken Casserole with Parmesan

Garlic Mushroom Chicken Casserole with Parmesan is a creamy, comforting dinner made with browned chicken, savory mushrooms, garlic, chicken broth, heavy cream, and freshly grated Parmesan. The casserole takes about 20 minutes to prepare and 35–40 minutes to cook, making it a practical one-dish meal for 4–6 servings.

Every bite combines tender chicken with richly browned mushrooms and a silky garlic-Parmesan sauce. A bubbling layer of mozzarella or extra Parmesan creates a golden finish, while fresh parsley adds a bright, herbaceous touch to this cozy family dinner.

Why You’ll Love This Recipe

This chicken casserole is the kind of dinner that feels special enough for guests but simple enough for a busy weeknight. The skillet-to-oven method builds flavor in layers, beginning with browned chicken and ending with a creamy sauce that clings to every piece.

Mushrooms bring a deep, savory character, while garlic and Italian seasoning give the sauce a familiar comfort-food aroma. Parmesan adds salty richness without making the sauce heavy or overly sharp, and the optional mozzarella creates a stretchy, golden topping.

If creamy chicken dinners are a favorite in your home, you may also enjoy this creamy garlic Parmesan chicken pasta for another cozy meal idea.

Ingredients You’ll Need

The ingredient list is straightforward, but each item has an important role. Choose boneless, skinless breasts for a leaner casserole or boneless thighs when you prefer especially tender chicken.

• Chicken: Use 1 1/2 pounds of chicken cut into evenly sized 1-inch pieces so it cooks at the same rate.
• Mushrooms: Cremini or white mushrooms both work well. Slice them evenly so they brown at a similar pace.
• Aromatics and fat: Six garlic cloves, olive oil, and unsalted butter provide the fragrant foundation of the casserole.
• Sauce ingredients: Flour thickens the broth and cream, while Parmesan gives the sauce its signature savory flavor.
• Seasonings: Kosher salt, black pepper, Italian seasoning, and optional red pepper flakes balance the creamy ingredients.
• Topping: Add 1 cup shredded mozzarella or additional Parmesan, then finish with the specified 2 tablespoons Parmesan and fresh parsley.

Freshly grated Parmesan is worth the small extra effort. It melts more smoothly than many pre-shredded varieties and gives the sauce a cleaner, more pronounced cheese flavor.

How to Make It Step-by-Step

Step 1: Begin by heating the oven to 375°F and lightly greasing a 9-by-13-inch baking dish. Having the dish ready before you start browning keeps the cooking process organized and makes transferring the chicken quick.

Step 2: Pat the chicken pieces dry with paper towels, then season them with about 3/4 teaspoon of the kosher salt and all of the black pepper. Dry surfaces brown better, while seasoning before searing helps flavor the chicken from the start.

Step 3: Heat 1 tablespoon of olive oil in a large skillet over medium-high heat. Brown the chicken in batches for 2–3 minutes per side, stopping while the centers are still undercooked, and transfer the pieces to the baking dish.

Step 4: Add the remaining tablespoon of olive oil to the skillet, followed by the sliced mushrooms. Cook for 6–8 minutes, stirring occasionally, until their moisture has cooked away and their edges are golden brown.

Step 5: Reduce the skillet heat to medium and add 2 tablespoons of butter with the minced garlic. Cook for 30–60 seconds, watching closely so the garlic becomes fragrant without turning bitter.

Step 6: Stir in the remaining 2 tablespoons of butter and sprinkle in the flour. Cook for 1 minute while stirring constantly, which removes the raw flour taste and prepares the skillet for the liquid ingredients.

Step 7: Gradually whisk in the low-sodium chicken broth, taking a moment to smooth out any floury lumps before adding the heavy cream. Stir in the Italian seasoning, remaining salt, and red pepper flakes if using, then simmer for 3–5 minutes until the sauce is slightly thickened.

Step 8: Take the skillet off the heat and stir in the 1/2 cup freshly grated Parmesan. Removing the sauce from direct heat helps the cheese melt evenly and keeps the finished sauce smooth rather than grainy.

Step 9: Pour the mushroom-Parmesan sauce over the chicken in the baking dish, making sure the pieces are well covered. Sprinkle the top with the optional mozzarella or additional Parmesan, followed by the extra 2 tablespoons Parmesan.

Step 10: Bake the casserole uncovered for 25–30 minutes, until the sauce is bubbling around the edges and the chicken reaches 165°F in the thickest pieces. Because oven performance and chicken piece sizes vary, use an instant-read thermometer to verify doneness.

Step 11: Rest the casserole for 5–10 minutes before serving. This brief pause allows the sauce to settle and makes it easier to spoon generous portions without the sauce running immediately across the plate.

Pro Tips for the Best Casserole

Give the mushrooms room. Crowding the skillet traps steam and can leave mushrooms pale and watery. If needed, cook them in batches or use a wide skillet so they sit in a mostly single layer.

Do not overcook the chicken before baking. The initial skillet browning is meant to create color and flavor, not to cook the pieces completely. The oven finishes the chicken gently in the sauce, helping it stay juicy.

Control the sauce thickness. The sauce should be slightly thickened before it goes into the oven, but it does not need to be as thick as a finished gravy. It will continue to thicken as it bakes and rests.

Adjust the heat to your taste. The crushed red pepper flakes are optional. Leave them out for a mild family-friendly casserole, or include the 1/4 teaspoon for a subtle warmth that complements the garlic.

For a lighter-tasting side, consider serving this dinner with cauliflower rice; this garlic butter chicken and Parmesan cauliflower rice offers another useful pairing idea.

Serving Ideas and Variations

This casserole is rich enough to pair beautifully with simple sides. Spoon it over pasta, rice, or mashed potatoes so the starch can catch the creamy sauce, or serve it with crusty bread for soaking up every last spoonful.

A crisp green salad, steamed broccoli, or roasted green beans adds freshness and color to the plate. Since the casserole already contains cream and cheese, a vegetable side with a little acidity can make the whole meal feel balanced.

• Pasta variation: Stir 8 ounces of cooked penne or rigatoni into the baking dish before adding the sauce for a fuller casserole.
• Thigh variation: Replace the chicken breasts with boneless chicken thighs for a tender, richer result.
• Cream cheese variation: Use 4 ounces softened cream cheese in place of part of the heavy cream for a thicker sauce.
• Bacon variation: Add 6–8 ounces cooked bacon for smoky, salty flavor.
• Spinach variation: Stir in 2 cups fresh spinach before baking and allow it to wilt into the warm sauce.

For another baked chicken dinner with a different cheese profile, take a look at this Swiss chicken casserole. Those who enjoy a crisp, classic Parmesan topping can also compare it with this classic chicken Parmesan.

Storage and Reheating

Cool leftovers promptly and store them in an airtight container in the refrigerator. The casserole is best enjoyed within a few days, and the sauce may thicken as it chills.

Reheat individual portions gently in the microwave, stirring or rotating as needed, or warm larger portions covered in a moderate oven until hot throughout. If the sauce seems especially thick after refrigeration, a small splash of chicken broth or cream can help loosen it.

For a make-ahead dinner, prepare the chicken, mushrooms, and sauce as directed, then assemble the casserole and refrigerate it until ready to bake. Allow extra time for a chilled casserole to heat through, and always confirm that the chicken reaches 165°F before serving.

If you like hearty baked meals with familiar savory flavors, this chicken bacon ranch casserole is another satisfying recipe to add to your dinner rotation.

Garlic Mushroom Chicken Casserole with Parmesan

Tender browned chicken and mushrooms are baked in a creamy garlic-Parmesan sauce until bubbling and golden. Serve this comforting casserole with pasta, rice, mashed potatoes, or crusty bread.

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Prep Time 20 minutes mins

Cook Time 35 minutes mins

Total Time 1 minute min

Servings: 4 servings

Ingredients Method Notes

Ingredients

  

Chicken and Seasoning

• 1 1/2 lb Boneless, skinless chicken breasts or thighs, cut into 1-inch pieces
• 1 tsp Kosher salt
• 1/2 tsp Freshly ground black pepper
• 2 tbsp Olive oil

Sauce

• 16 oz Cremini or white mushrooms, sliced
• 4 tbsp Unsalted butter
• 6 cloves Garlic, minced
• 3 tbsp All-purpose flour
• 2 cups Low-sodium chicken broth
• 1 cup Heavy cream
• 1/2 cup Freshly grated Parmesan cheese
• 1 tsp Italian seasoning
• 1/4 tsp Crushed red pepper flakes, optional

Topping and Garnish

• 2 tbsp Parmesan cheese for topping
• 1 cup Shredded mozzarella or additional Parmesan, optional
• 2 tbsp Fresh parsley, chopped

Method

 

Step-by-Step

1. Heat the oven to 375°F and lightly grease a 9-by-13-inch baking dish.
2. Pat the chicken dry and season it with about 3/4 teaspoon of the kosher salt and all of the black pepper.
3. Heat 1 tablespoon olive oil in a large skillet over medium-high heat. Brown the chicken in batches for about 2–3 minutes per side, then transfer it to the prepared baking dish; it does not need to be fully cooked.
4. Add the remaining olive oil and sliced mushrooms to the skillet. Cook for 6–8 minutes, stirring occasionally, until the mushrooms release their moisture and become nicely browned.
5. Reduce the heat to medium and add 2 tablespoons butter with the minced garlic. Cook for 30–60 seconds, just until the garlic is fragrant.
6. Stir in the remaining 2 tablespoons butter. Sprinkle in the flour and cook for 1 minute, stirring constantly to form the base of the sauce.
7. Gradually whisk in the chicken broth, followed by the heavy cream. Add the Italian seasoning, remaining salt, and optional red pepper flakes, then simmer for 3–5 minutes until slightly thickened.
8. Remove the skillet from the heat and stir in the 1/2 cup Parmesan. Adding the cheese off the heat helps it melt into a smooth sauce.
9. Pour the mushroom-Parmesan sauce over the chicken in the baking dish. Sprinkle the top with the optional mozzarella and the additional 2 tablespoons Parmesan.
10. Bake the casserole uncovered for 25–30 minutes, until bubbling and the chicken reaches 165°F in the thickest pieces.
11. Let the casserole rest for 5–10 minutes before garnishing with parsley. Serve it with pasta, rice, mashed potatoes, or crusty bread.

Notes

For the best flavor, brown mushrooms in a single layer without crowding the skillet. Grate Parmesan from a wedge and add it off the heat. The chicken should finish cooking in the oven, and its internal temperature must reach 165°F.

Final Thoughts

Garlic Mushroom Chicken Casserole with Parmesan brings together everything a comforting dinner should offer: tender chicken, deeply browned mushrooms, fragrant garlic, and a creamy sauce with a bubbling cheese topping. It is easy to customize with pasta, spinach, bacon, or a different cheese while keeping the same dependable cooking method.

Take the time to brown the mushrooms properly, add the Parmesan off the heat, and avoid fully cooking the chicken during the first skillet step. After a short rest, you will have a warm, satisfying casserole that is ready to share with family or serve as a relaxed weekend dinner.