Creamy Chicken and Mushroom Cauliflower Rice Casserole is so comforting and delicious, it's hard to believe that it's actually low-carb and packed with healthy veggies. Made with shredded chicken meat, mushrooms and leeks, this easy dinner is incredibly flavorful and creamy, though it uses no cream or milk!

I also love this lightened up shepherd's pie with cauliflower topping.

chicken and mushroom cauliflower rice casserole in a white casserole dish on white background close up

I always get excited about casseroles! Something about the pure comfort they provide is unparalleled. Creamy casseroles, like this Broccoli Chicken Pasta Casserole, are the best kind, in my opinion, and this one is exceptionally creamy, thanks to the velvety sauce that combines cashews, coconut milk, nutritional yeast, garlic and chicken broth.

The bold flavors of mushrooms and leek and the creaminess of the sauce help to hide the cauliflower taste and if you don’t know it’s made with cauliflower rice, you may think it’s regular, soft cooked rice.

Don’t get me wrong, I DO love the taste of cauliflower. In some dishes though, and this one is a prime example, I like the cauliflower to be a culinary chameleon that will take on other flavors. In this creamy casserole the cauliflower is supposed to quietly replace regular rice, after all.

For more healthy comfort food recipes make sure you also check my Creamy Zucchini Mushroom Pasta, Pork Bolognese or Bone Broth Chicken Soup.

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Ingredient notes
How to make creamy chicken and mushroom cauliflower rice casserole
Storage, freezing & meal prep tips
Substitutions and special diets
Recipe
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Meet the Author

Ingredient notes

creamy chicken and mushrooms cauliflower rice casserole ingredients on white marble countertop

Cauliflower rice: For this particular recipe, I recommend using frozen cauliflower rice because it is easy to squeeze in a kitchen towel and remove most of its water content.
Chicken: Use cooked boneless skinless chicken breasts or thighs. Cook your own or use store bought rotisserie chicken. I like to reserve chicken breasts from a roasted whole chicken and use them for this recipe.
Mushrooms: Brown (baby bella) or button mushrooms will both work. I like brown better because they have a deeper flavor.
Cashews: Make sure to use raw and unsalted cashews.
Coconut milk: Use canned full fat coconut milk. Make sure to give it a shake before opening the can because the fat tends to solidify and separate from the liquid.
Leeks: Milder than onion, leeks go really well with chicken and I love the leek + chicken + mushroom combo. Don’t use the green part of leek. I cut it off, place in a zip lock bag, freeze it and use it in my homemade chicken stock or bone broth.
Nutritional yeast: Used to add a cheesy flavor to the sauce. Nutritional yeast is a grated parmesan cheese alternative that’s plant-based and it works very well in this dish.
Parmesan cheese: This is completely optional but I like to sprinkle some parmesan on top of the casserole before baking for a wonderfully crispy, roasted topping. For a dairy-free option just use more nutritional yeast.

How to make creamy chicken and mushroom cauliflower rice casserole

Soak the cashews for a couple hours before making the dish. While this is an important step to make a velvety smooth cashew cream, don’t stress about it if you forgot to soak the nuts for several hours. If you have a good blender, a quick soak in boiling water will do the trick.
Squeeze the moisture out of cauliflower rice. This is a crucial step that will prevent the casserole from getting watery and mushy. Just thaw the cauli rice until room temperature, place in a clean kitchen towel, make a little “packet” and squeeze using both hands oven the kitchen sink. Try to get as much liquid out as possible.
Cook mushrooms and leeks. Sauté mushrooms and leeks in ghee or oil until they start browning, 5-6 minutes. Add squeezed out cauliflower rice and chicken, and turn off the heat.

four steps of making creamy chicken and mushrooms cauliflower rice casserole

Make the sauce. Place soaked and drained cashews, coconut milk, fresh garlic and nutritional yeast in a high-speed blender and whizz it until smooth and creamy.
Assemble. Pour the sauce into the cauliflower rice mixture, season with salt and pepper, stir and transfer to a greased casserole dish. Sprinkle with parmesan or more nutritional yeast on top.

unbaked chicken and mushroom cauliflower rice casserole in a white oval casserole dish on white marble countertop

Bake and broil. Bake in 425 degrees Fahrenheit for about 20 minutes until nice and bubbly. Finish by broiling for a couple more minutes until the top is lightly brown. Watch the casserole while broiling so you don’t burn it. Take out of the oven and serve!

creamy chicken and mushroom cauliflower rice casserole baked on a kitchen towel in a white oval casserole dish

Storage, freezing & meal prep tips

As with most casseroles, this Creamy Chicken, Mushroom and Cauliflower Rice Casserole can be fully assembled ahead of time and stored in the fridge for a couple days. Just pop it in the oven when you’re ready to eat and you’ll have dinner on the table in less than 30 minutes. Because the dish will be very cold from the fridge, it may take a couple minutes more than 20 minutes to become hot and bubbly. Just check at the 20 minutes mark and add more time, if needed.
The casserole can be stored in airtight containers for up to 5 days and frozen for up to 6 months.
To reheat, just pop it in the microwave for a minute or 2 until heated through.

Try this Corned Beef and Cabbage for another classic comfort food dinner.

Substitutions and special diets

For Paleo/Whole30 version, don’t use parmesan cheese on top. Instead, just sprinkle some more nutritional yeast for an extra “cheesy” boost.
If you follow the Keto diet and do eat dairy, feel free to replace nutritional yeast with parmesan cheese all together.
For a vegan version, skip the chicken and cheese and use vegetable broth instead of chicken broth. This is a very versatile dish and though it has “chicken” in the title, the mushrooms and leeks have enough flavor to make it completely plant-based and delicious.
If you are looking for a healthier rice and chicken casserole but don’t like or have cauliflower rice, just use cooked brown rice place of cauliflower. No need to squeeze the moisture out from the rice!

creamy chicken and mushroom cauliflower rice casserole in a white oval dish with some casserole taken out

More low-carb dinner ideas

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Meet the Author

Hi, I'm Agnieszka. I'm a mom of three and recipe developer, writer and photographer behind Wholly Tasteful. I love creating comforting, delicious, family-friendly recipes that you can feel good about.

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