Chicken Spinach Mushroom Low Carb Oven Dish

Featured in: Quick Weeknight Meals

This satisfying oven-baked dish combines tender chunks of cooked chicken with sautéed fresh spinach and sliced mushrooms, all bound together in a rich, creamy sauce. Heavy cream creates a luscious base while melted mozzarella and grated parmesan form a golden, bubbly topping. The entire casserole comes together in just 40 minutes, making it an ideal choice for busy evenings when you want something hearty without the heavy carbs.

What makes this dish particularly convenient is how well it reheats—the flavors actually deepen overnight, making it excellent for meal prep. You can use rotisserie chicken to streamline preparation, and the vegetable mixture can be sautéed ahead of time.

Updated on Sat, 07 Feb 2026 09:15:00 GMT
Golden, bubbly low-carb Chicken Spinach & Mushroom casserole fresh from the oven with melted cheese. Pin
Golden, bubbly low-carb Chicken Spinach & Mushroom casserole fresh from the oven with melted cheese. | forkandbloom.com

The first time I threw this together, I was staring at a rotisserie chicken from the grocery store and a container of spinach that needed to be used immediately. It was one of those Tuesday evenings where creativity was born from necessity, and honestly, it has become a regular request ever since.

My sister stayed over last month while she was doing keto, and I made this for dinner. She literally asked for the recipe before she even finished her first serving, then texted me two days later saying she had already made it twice. That is when I knew this was not just a throw together meal anymore.

Ingredients

  • 2 cups cooked chicken breast: Rotisserie chicken works perfectly here, or use leftover roasted chicken from earlier in the week
  • 4 cups fresh spinach: Do not skip the step of sauteing this down first, otherwise you will end up with too much liquid in your final dish
  • 2 cups mushrooms, sliced: Baby bellas or cremini mushrooms give you more flavor than white button mushrooms
  • 1 small onion, finely chopped: Yellow onion works best, but red onion adds a nice sweetness if that is what you have
  • 3 cloves garlic, minced: Fresh garlic makes a noticeable difference here compared to garlic powder
  • 1 cup mozzarella cheese, shredded: Buy a block and shred it yourself for better melting, though pre shredded works in a pinch
  • 1/4 cup parmesan cheese, grated: The finer the grate, the more evenly it distributes throughout the dish
  • 1/2 cup heavy cream: This creates the creamy sauce base without any thickeners needed
  • 2 tablespoons olive oil: You need enough fat to properly saute the vegetables
  • 1 teaspoon Italian seasoning: Add more if you really love herbs, but this amount keeps it balanced
  • Salt and pepper, to taste: Remember the parmesan is already salty, so taste as you go

Instructions

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Get your oven ready:
Preheat to 375°F and grease a 9x13 inch dish with a little butter or oil
Sauté the vegetables:
Heat olive oil in a large skillet over medium heat, then cook onions and mushrooms for 5 to 7 minutes until they soften and start to turn golden brown
Add the aromatics:
Stir in the garlic for just 1 minute until you can smell it, then toss in the spinach and cook until it wilts down completely
Season the mixture:
Add your salt, pepper, and Italian seasoning right in the pan, tasting and adjusting as needed
Layer the chicken:
Spread your cooked chicken evenly across the bottom of your prepared casserole dish
Add the vegetable layer:
Spoon all that sautéed spinach and mushroom mixture over the chicken in an even layer
Drizzle the cream:
Pour the heavy cream slowly over the top so it can seep down through all the layers
Add the cheese:
Sprinkle both the mozzarella and parmesan over the entire surface until everything is covered
Bake until golden:
Bake uncovered for 20 to 25 minutes until the cheese is melted and bubbling with golden brown spots
Let it rest:
Wait 5 minutes before serving so everything sets and you get nice clean servings
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Tender chicken, wilted spinach, and earthy mushrooms layered in a creamy, gluten-free weeknight dinner. Pin
Tender chicken, wilted spinach, and earthy mushrooms layered in a creamy, gluten-free weeknight dinner. | forkandbloom.com

Last week I made this for a friend who insists she hates casseroles, and she proceeded to have seconds. Sometimes the simplest combinations end up being the ones people ask for over and over again.

Make It Your Own

I have started adding artichoke hearts sometimes when I want something extra, and sun dried tomatoes work beautifully too. The base recipe is forgiving enough that you can play with it once you have made it a few times.

Perfect Sides

Cauliflower rice is the obvious low carb pairing, but sometimes I just serve it with a simple green salad with lemon vinaigrette. The acid cuts through all that rich cheese and cream perfectly.

Storage And Reheating

This keeps in the refrigerator for up to 4 days in an airtight container, and I honestly think it tastes better on day two. The flavors have time to meld together in a way they just cannot right out of the oven.

  • Reheat individual portions in the microwave for 2 to 3 minutes
  • Cover with foil if reheating the entire dish in the oven at 350°F
  • Add a splash of cream if it seems dry after reheating
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Sliced, cheesy low-carb Chicken Spinach & Mushroom oven dish served hot with a golden crust. Pin
Sliced, cheesy low-carb Chicken Spinach & Mushroom oven dish served hot with a golden crust. | forkandbloom.com

There is something deeply satisfying about a dish that comes together so quickly but tastes like it took all day. Enjoy every bite of this one.

Recipe Q&A

Can I make this ahead of time?

Yes, you can assemble the entire casserole up to 24 hours in advance and store it covered in the refrigerator. Bake when ready, adding a few extra minutes if baking cold.

Can I freeze leftovers?

Absolutely. Portion cooled leftovers into airtight containers and freeze for up to 3 months. Thaw overnight in the refrigerator before reheating at 350°F until warmed through.

What can I substitute for heavy cream?

Half-and-half works but yields a thinner consistency. For a dairy-free option, full-fat coconut cream can be used, though it will slightly alter the flavor profile.

How do I prevent a watery casserole?

Sauté the mushrooms and spinach thoroughly until all moisture evaporates. This step is crucial—excess water from vegetables can make the final dish soggy.

Can I use uncooked chicken?

You'll need to adjust the method. Cube raw chicken breast and cook it in the skillet after sautéing the vegetables, ensuring it reaches 165°F internally before assembling the casserole.

How do I know when it's done baking?

The casserole is ready when the cheese is melted and golden brown, typically 20-25 minutes. You should see bubbling around the edges and the cheese should have slight browned spots.

Chicken Spinach Mushroom Low Carb Oven Dish

Creamy, protein-packed casserole with tender chicken, spinach, and mushrooms—perfect for flavorful low-carb weeknight meals.

Prep duration
15 min
Cooking duration
25 min
Complete duration
40 min


Skill level Easy

Origin American

Yield 4 Portions

Dietary specifications Gluten-free, Low-Carb

Components

Proteins

01 2 cups cooked chicken breast, chopped or shredded

Vegetables

01 4 cups fresh spinach
02 2 cups mushrooms, sliced
03 1 small onion, finely chopped
04 3 cloves garlic, minced

Dairy

01 1 cup mozzarella cheese, shredded
02 1/4 cup parmesan cheese, grated
03 1/2 cup heavy cream

Oils & Seasonings

01 2 tablespoons olive oil
02 1 teaspoon Italian seasoning
03 Salt and pepper, to taste

Directions

Step 01

Preheat Oven: Preheat oven to 375°F. Lightly grease a 9×13 inch casserole dish.

Step 02

Sauté Vegetables: In a large skillet, heat olive oil over medium heat. Add onions and mushrooms; sauté for 5–7 minutes until soft and lightly browned.

Step 03

Add Aromatics: Add garlic and cook for 1 minute until fragrant.

Step 04

Wilt Spinach: Stir in spinach and cook until wilted. Season the mixture with salt, pepper, and Italian seasoning.

Step 05

Layer Chicken: Spread the cooked chicken evenly across the bottom of the prepared casserole dish.

Step 06

Add Vegetable Layer: Layer the sautéed mushroom, spinach, and onion mixture over the chicken.

Step 07

Add Cream: Drizzle heavy cream evenly over the top.

Step 08

Add Cheese: Sprinkle mozzarella and parmesan cheese over the entire dish.

Step 09

Bake: Bake uncovered for 20–25 minutes, or until the cheese is melted and golden brown.

Step 10

Rest and Serve: Remove from oven and let rest for 5 minutes before serving.

Necessary tools

  • Large skillet
  • 9×13 inch casserole dish
  • Chef's knife
  • Cutting board
  • Mixing spoon
  • Measuring cups and spoons

Allergy details

Review each ingredient for potential allergens and consult healthcare professionals if you're uncertain about anything.
  • Contains dairy (mozzarella, parmesan, heavy cream)
  • Contains possible traces of lactose
  • Gluten-free if all ingredients are certified gluten-free

Nutritional information (per portion)

These values are provided as estimates only and shouldn't replace professional medical guidance.
  • Calories: 390
  • Fat: 26 g
  • Carbs: 6 g
  • Protein: 32 g