Creamy Spinach, Mushroom & Chicken Bake
Yield: 6 servings
Prep: 20 minutes
Cook: 35–45 minutes
Total: about 1 hour
Ingredients
Chicken
2 lb (900 g) boneless, skinless chicken breasts or thighs
1 tbsp olive oil
1 tsp sal
½ tsp black pepper
1 tsp garlic powder
½ tsp paprika
½ tsp Italian seasoning
Mushrooms & spinach
16 oz (450 g) fresh mushrooms, sliced
5–6 oz (140–170 g) fresh spinach
1 medium onion, finely diced
3 cloves garlic, minced
1 tbsp butter
1 tbsp olive oil
Creamy sauce
1 cup (240 ml) heavy cream
4 oz (115 g) cream cheese, softened
½ cup (120 ml) chicken broth
½ cup (50 g) grated Parmesan
½ tsp Italian seasoning
¼ tsp black pepper
¼ tsp salt, or to taste
½ tsp Dijon mustard — optional
¼ tsp red pepper flakes — optional
Cheese topping
1½ cups (150–170 g) shredded mozzarella
½ cup (50 g) shredded Parmesan
Optional: ½ cup shredded provolone
Full Recipe
1. Prepare the chicken
Preheat your oven to:
375°F (190°C).
Pat the chicken dry.
If using thick chicken breasts, slice them horizontally into thinner cutlets or pound them to approximately ½–¾ inch thick.
Season both sides with:
Salt
Pepper
Garlic powder
Paprika
Italian seasoning
2. Brown the chicken
Heat 1 tablespoon olive oil in a large oven-safe skillet over medium-high heat.
Add the chicken and sear for approximately 2–3 minutes per side.
You don’t need to cook it completely at this stage.
Remove the chicken and set aside.
Browning the chicken first adds much more flavor than putting completely raw chicken straight into the casserole.
Add butter and another tablespoon of olive oil to the pan.
Add the sliced mushrooms.
Cook for approximately 6–8 minutes, stirring occasionally.
Initially, the mushrooms will release quite a bit of liquid. Continue cooking until most of that moisture evaporates and the mushrooms begin to brown.
Add the diced onion and cook for another 3–4 minutes.
Add minced garlic and cook for 30–60 seconds.
4. Add the spinach
Add the spinach a handful at a time.
Cook for approximately 2–3 minutes, stirring until it wilts.
If using frozen spinach, thaw it first and squeeze out excess water very well.
5. Make the creamy sauce
Reduce the heat to medium-low.
Add:
Heavy cream
Chicken broth
Cream cheese
Parmesan
Italian seasoning
Black pepper
Dijon mustard, if using
Stir continuously until the cream cheese melts and the sauce becomes smooth.
Simmer gently for approximately 3–5 minutes.
Do not aggressively boil the cream sauce.
Taste and adjust the salt.
6. Assemble the casserole
Return the browned chicken to the skillet.
If you’re using a separate baking dish, transfer the mushroom-spinach mixture and sauce into a greased 9 × 13-inch baking dish, then arrange the chicken pieces throughout.
Spoon some sauce over the chicken.
Cover the top with:
Mozzarella
Parmesan
Optional provolone
You want a generous cheese layer like the one visible in the photograph.
7. Bake
Place uncovered in the preheated oven.
Bake for approximately:
25–30 minutes at 375°F (190°C)
until the chicken is fully cooked and the sauce is bubbling.
The chicken should reach an internal temperature of 165°F (74°C) at the thickest point.
8. Brown the cheese
For the characteristic browned, blistered cheese shown in the picture, switch the oven to broil/grill for approximately 1–3 minutes.
Watch it constantly.
The cheese can go from golden to burnt very quickly.
9. Rest
Remove the casserole from the oven and allow it to rest for 5–10 minutes.
This lets the sauce thicken slightly and makes serving much easier.
Garnish with:
Fresh parsley
Fresh basil
Chopped green onion
A little Parmesan
The Secret to a Better Casserole
Don’t crowd the mushrooms.
If mushrooms are crowded in the pan, they’ll steam instead of brown.
For especially flavorful mushrooms, cook them in two batches.
Don’t skip browning the chicken.
The browned surface adds a roasted flavor that you won’t get from simply baking raw chicken.
Drain spinach properly.
Excess spinach water can turn your creamy sauce thin.
Use freshly grated cheese.
Freshly grated mozzarella and Parmesan generally melt more smoothly than some pre-shredded cheeses.
Serving Suggestions
This casserole is rich, so pair it with something fresh.
Low-carb
Green salad
Roasted asparagus
Broccoli
Cauliflower mash
Green beans
With carbohydrates
Garlic bread
Crusty French bread
Rice
Pasta
Mashed potatoes
Egg noodles
My favorite
Serve it with garlic bread + a simple lemon-dressed green salad. The acidity of the salad cuts through the creamy sauce.
Easy Variations
Chicken, spinach & mushroom Alfredo
Replace the homemade cream sauce with approximately 2 cups Alfredo sauce.
Add Parmesan and mozzarella and bake as directed.
Garlic Parmesan version
Increase garlic to 5 cloves and use:
Parmesan
Mozzarella
½ tsp garlic powder
Finish with fresh parsley.
Bacon version
Cook 6 slices of bacon, crumble them and add them to the casserole before adding the cheese.
This works particularly well with mushrooms.
Broccoli version
Replace half of the spinach with approximately 2 cups lightly steamed broccoli.
Sun-dried tomato version
Add ½ cup chopped sun-dried tomatoes.
The tomatoes provide acidity and sweetness that work beautifully with the creamy sauce.
Nut & Allergen Information
Does this recipe contain nuts?
No. The basic recipe contains no peanuts or tree nuts.
However, check packaged ingredients such as:
Cream cheese
Shredded cheese
Chicken broth
Seasoning mixes
Prepared sauces
for manufacturer cross-contact warnings.
Major allergens
This recipe contains:
Milk/dairy
Potentially soy, depending on packaged ingredients
Chicken, mushrooms, spinach, garlic, onion and the basic seasonings are not inherently nut-containing.
Gluten
The basic recipe can be gluten-free, but check:
Chicken broth
Seasonings
Cream cheese
Pre-shredded cheese
Any prepared sauce
for gluten-containing additives or cross-contact.
If serving someone with celiac disease, use products specifically labeled gluten-free.
Approximate Nutrition
Assuming 6 servings and the ingredients above:
Nutrient Approx. per serving
Calories 550–650 kcal
Protein 50–55 g
Fat 35–42 g
Carbohydrates 8–12 g
Fiber 2–3 g
Net carbs 6–9 g
Sugar 3–5 g
Sodium 700–1,000 mg
These are estimates. The actual numbers depend heavily on the chicken cut, cream cheese, cheese quantities and broth.
Recipe Q&A
Can I use chicken thighs?
Yes. Boneless skinless thighs are excellent here and tend to stay juicier than breast meat.
Can I use frozen spinach?
Yes. Thaw it completely and squeeze out as much water as possible.
Can I use frozen mushrooms?
Fresh mushrooms are strongly preferred. Frozen mushrooms release considerably more water and won’t brown as nicely.
Can I prepare this ahead?
Yes.
Assemble the casserole, cover and refrigerate for up to about 24 hours before baking.
If baking directly from the refrigerator, expect it to need additional time.
Can I freeze it?
Yes, although cream-based sauces can sometimes change texture slightly after freezing and thawing.
For best results, cool completely, package airtight and use within approximately 2–3 months.
Why is my sauce watery?
The most common causes are:
Mushrooms weren’t cooked long enough.
Spinach contained excess water.
Too much broth was added.
The casserole wasn’t allowed to rest.
Cook the mushrooms until their released liquid has largely evaporated.
Can I make it without cream cheese?
Yes.
Replace the 4 oz cream cheese with approximately ½ cup additional heavy cream + ¼ cup Parmesan.
The sauce will be somewhat thinner but still creamy.
Can I use half-and-half?
Yes, although heavy cream produces a richer, thicker sauce.
If using half-and-half, simmer the sauce a little longer to reduce it.
Can I use pre-cooked chicken?
Yes.
Use approximately 3–4 cups cooked chicken, add it during assembly, and reduce the baking time to approximately 15–20 minutes, just long enough to heat everything and melt/brown the cheese.
How do I prevent the cheese from burning?
Bake the casserole on the center rack and only use the broiler at the very end.
Keep your eyes on it while broiling.
Can I make this in a slow cooker?
Yes, but I don’t recommend it for this particular dish because the mushrooms and cheese won’t develop the same browned appearance as the casserole in the photograph.
What cheese gives the best result?
A combination is best:
Mozzarella + Parmesan + a little provolone.
Mozzarella provides the stretchy melted layer, Parmesan gives salty flavor and browning, and provolone adds richness.
Best Version at a Glance
Chicken: 2 lb
Mushrooms: 16 oz
Spinach: 5–6 oz
Heavy cream: 1 cup
Cream cheese: 4 oz
Parmesan: 1 cup total, divided
Mozzarella: 1½ cups
Oven: 375°F / 190°C
Bake: 25–30 minutes
Broil: 1–3 minutes
Rest: 5–10 minutes
