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Are you often asking yourself, “What will I cook tonight?” I know I do! When weeknights get hectic, I reach for recipes that promise big flavor without a big fuss. That is exactly what I created with this incredible Keto Mushroom Chicken Casserole. It is a simple, satisfying, and utterly delicious meal perfect for those busy evenings when you crave comfort food but need to keep things low-carb. I can usually get this dish prepped and cooked in about 30-40 minutes, meaning a hearty, flavorful dinner is on your table in no time.

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Why This Keto Mushroom Chicken Casserole Will Be Your New Favorite

I absolutely adore this Keto Mushroom Chicken Casserole for so many reasons, and I think you will too. It ticks all the boxes for a truly great weeknight meal.

Incredible Flavor in Every Bite: The combination of tender chicken, savory mushrooms, and a rich, creamy sauce is simply irresistible. It tastes like a dish you spent hours on, but it is surprisingly quick.
Effortless & Quick Preparation: I designed this recipe to be straightforward, using readily available ingredients and simple steps. It is perfect for those busy days when you need a delicious meal without the stress.
Perfectly Low-Carb: For anyone following a ketogenic or low-carb lifestyle, this casserole is a dream come true. It is packed with healthy fats and protein, keeping you full and satisfied without compromising your dietary goals.
Versatile & Adaptable: This dish is wonderfully forgiving, making it easy to adapt to what you have on hand. It is a true crowd-pleaser that fits perfectly into any family dinner rotation.

Equipment You’ll Need

Making this Keto Mushroom Chicken Casserole is quite simple, and you likely have most of the equipment already in your kitchen.

Heavy Skillet (10-12 inch): A good quality heavy-bottomed skillet is essential for searing the chicken and mushrooms beautifully.
Tongs: For easy handling and flipping of chicken and mushrooms.
Measuring Cups and Spoons: For accurate ingredient measurements.
Sharp Knife and Cutting Board: For prepping your chicken and mushrooms.
Whisk: To ensure a smooth, creamy sauce.

Ingredients for Your Keto Mushroom Chicken Casserole

I always emphasize starting with fresh, high-quality ingredients for the best flavor and nutritional value. Here is everything you will need to make this amazing Keto Mushroom Chicken Casserole.

1 pound chicken tenderloin
1/2 pound mushrooms (thickly sliced)
2 tbsp butter
2 tbsp olive oil
2 cloves garlic (crushed)
1/4 cup fresh parsley (chopped)
2 tbsp fresh thyme leaves
salt and pepper
1/2 cup chicken stock
1/2 cup heavy cream
1/4 cup sour cream

How to Make This Creamy Keto Mushroom Chicken Casserole (Step-by-Step)

I always aim for clear, concise instructions, so you can cook with confidence. Imagine some helpful photos here, showing the golden-brown chicken and the beautifully rich sauce coming together.

Heat half of the butter and half of the olive oil in a heavy skillet over medium high heat.
Season the chicken tenders and then sear in batches until browned on all sides. Remove from skillet and set aside.
Add the rest of the butter and oil to the skillet and cook the mushrooms until they are browned and crispy.
Add the garlic, herbs and chicken stock and deglaze the pan, scraping all of the good stuff from the bottom of the pan.
Add the cream and sour cream and simmer until sauce starts to thicken. Do not boil, as cream could split.
Return the tenderloins to the pan and toss through the sauce. Cook for five more minutes. or until internal temperature of the chicken is 165 degrees F.
Store, covered, in the refrigerator for up to 5 days.

Maya Anderson

Simple Keto Mushroom Chicken Casserole Recipe

This Keto Mushroom Chicken Casserole is a simple, satisfying, and utterly delicious meal perfect for those busy evenings when you crave comfort food but need to keep things low-carb. It promises big flavor without a big fuss, typically ready in 30-40 minutes.

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Prep Time 10

Cook Time 20

Total Time 30

Servings: 4 servings

Course: chicken, Dinner

Cuisine: American

Calories: 400

Ingredients Equipment Method Notes

Ingredients

1 pound chicken tenderloin
1/2 pound mushrooms thickly sliced
2 tablespoon butter
2 tablespoon olive oil
2 cloves garlic crushed
1/4 cup fresh parsley chopped
2 tablespoon fresh thyme leaves
salt and pepper
1/2 cup chicken stock
1/2 cup heavy cream
1/4 cup sour cream

Equipment

Heavy Skillet (10-12 inch)
Tongs
Measuring cups and spoons
sharp knife
Cutting board
Whisk

Method

Heat half of the butter and half of the olive oil in a heavy skillet over medium high heat.
Season the chicken tenders and then sear in batches until browned on all sides. Remove from skillet and set aside.
Add the rest of the butter and oil to the skillet and cook the mushrooms until they are browned and crispy.
Add the garlic, herbs and chicken stock and deglaze the pan, scraping all of the good stuff from the bottom of the pan.
Add the cream and sour cream and simmer until sauce starts to thicken. Do not boil, as cream could split.
Return the tenderloins to the pan and toss through the sauce. Cook for five more minutes. or until internal temperature of the chicken is 165 degrees F.
Store, covered, in the refrigerator for up to 5 days.

Notes

Chicken tenderloins are great for quick cooking, but you can also use boneless, skinless chicken thighs (cut into 1-inch pieces) or chicken breast. For mushrooms, cremini or white button are standard, but feel free to try shiitake or oyster. Heavy cream can be swapped for full-fat coconut cream or cashew cream, and sour cream for unsweetened full-fat coconut yogurt or dairy-free cashew sour cream. Dried herbs can substitute fresh, but use sparingly. Other vegetables like cauliflower florets, broccoli florets, or chopped spinach can be added.

For a good sear on chicken, ensure the skillet is hot and avoid overcrowding; cook in batches. Season generously. If using pre-cooked chicken, shred and add at the end to warm through. For mushrooms, wipe clean with a damp cloth instead of rinsing, slice thickly, and cook in a single layer without constant stirring to develop flavor and crispness.

Elevate flavor by whisking 1-2 teaspoons of Dijon mustard into the sauce, adding 1 teaspoon of Worcestershire sauce (check carbs) when deglazing, stirring in 2 ounces of softened cream cheese for richness, sprinkling 1/4 cup freshly grated Parmesan into the sauce, topping with crumbled bacon bits, or adding 1/4 teaspoon red pepper flakes with garlic for a subtle kick.

To avoid a watery casserole, ensure mushrooms sear, not steam. If sauce is watery, simmer longer, uncovered, over low heat to reduce. Prevent dry chicken by not overcooking during initial sear; aim for a brown crust and finish cooking in the sauce to 165°F. If the sauce isn’t thickening, ensure a gentle simmer (not a boil) and allow more time. A pinch of xanthan gum or cream cheese can help in a pinch.

For meal prep, slice mushrooms and crush garlic a day or two in advance. Pre-season chicken tenderloins a few hours before cooking. Store cooked casserole in an airtight container in the refrigerator for up to 5 days. Reheat gently on the stovetop or in the microwave, adding a splash of stock or cream if needed. The baked casserole can be frozen for up to 3 months; thaw overnight before reheating. Do not freeze the casserole raw due to dairy separation risks.

Serve this casserole with steamed green beans or asparagus, cauliflower rice to soak up the sauce, a simple side salad with vinaigrette, or roasted broccoli for a balanced meal.

Pro Tips for the Perfect Keto Mushroom Chicken Casserole

I want you to achieve the best results every time you make this dish. Here are some of my favorite tips to ensure your Keto Mushroom Chicken Casserole is absolutely perfect.

Getting the Best Sear on Your Chicken

Achieving a good sear on your chicken tenderloins is key for maximum flavor. I always make sure my skillet is hot enough before adding the chicken. Also, do not overcrowd the pan; cook the chicken in batches if necessary so each piece gets proper contact with the hot surface. Season the chicken generously with salt and pepper right before searing. If I am using pre-cooked chicken, like rotisserie, I shred it and add it at the very end with the sauce, just to warm through.

Mastering Your Mushrooms

Mushrooms need some special attention to really shine. I like to wipe them clean with a damp cloth instead of rinsing them, as they absorb water easily. Slicing them thickly ensures they do not shrink away to nothing during cooking. For that beautiful browned and crispy texture, I cook them in a single layer, giving them space in the pan. Resist the urge to stir them constantly; let them sit undisturbed for a few minutes to develop that deep, earthy flavor.

Elevating Flavor: Beyond Salt and Pepper

While salt and pepper are essential, I love to add a few extra touches to really make this Keto Mushroom Chicken Casserole sing. Here are some keto-friendly flavor boosters I often use:

Flavor Booster	How to Incorporate
Dijon Mustard	Whisk 1-2 teaspoons into the sauce along with the creams.
Worcestershire Sauce	Add 1 teaspoon to the pan when deglazing with chicken stock (check for carbs).
Cream Cheese	Stir in 2 ounces of softened cream cheese with the heavy cream for extra richness.
Parmesan Cheese	Sprinkle 1/4 cup freshly grated Parmesan into the sauce, or over top before serving.
Bacon Bits	Cook 2-3 slices of bacon until crispy, crumble, and sprinkle over the finished dish.
Red Pepper Flakes	Add 1/4 teaspoon with the garlic for a subtle kick.

Making Ahead, Storing & Freezing Your Keto Mushroom Chicken Casserole

This Keto Mushroom Chicken Casserole is fantastic for meal prep! I love making a big batch and having it ready for busy weeknights.

Meal Prep & Make-Ahead Tips

I often prep components of this casserole in advance to save time. I can slice my mushrooms and crush the garlic a day or two before. I also find that pre-seasoning the chicken tenderloins a few hours before cooking can help them absorb flavor. While I do not recommend fully assembling the cooked casserole too far in advance, having your ingredients prepped makes the cooking process incredibly fast when you are ready to eat.

Storing and Reheating Leftovers

Storing leftovers is simple. Once the Keto Mushroom Chicken Casserole has cooled completely, I transfer it to an airtight container and store it in the refrigerator. It will keep beautifully for up to 5 days, just as the recipe states. To reheat, I gently warm it on the stovetop over low heat, adding a splash of chicken stock or heavy cream if the sauce seems too thick. I can also microwave individual portions until heated through.

Freezing Baked vs. Unbaked Casserole

Freezing this casserole is a great option for future meals!

Freezing Baked Casserole: After the casserole is fully cooked and cooled, I transfer it to a freezer-safe, airtight container or a freezer bag. It can be frozen for up to 3 months. To reheat, I thaw it overnight in the refrigerator and then warm it in a skillet or oven until heated through.
Freezing Unbaked Casserole: I do not recommend freezing this particular casserole raw, as the dairy components might separate upon thawing and baking, affecting the sauce’s texture.

Scaling the Recipe for Any Crowd

This Keto Mushroom Chicken Casserole recipe is wonderfully easy to scale. If I am feeding a larger crowd, I simply double all the ingredients. I make sure to use a larger skillet or cook the chicken and mushrooms in separate batches to avoid overcrowding. For a smaller portion, I can halve all the ingredients. Just remember that cooking times might need slight adjustments when scaling; always check the chicken’s internal temperature.

What to Serve with Keto Mushroom Chicken Casserole

This rich and creamy Keto Mushroom Chicken Casserole is quite satisfying on its own, but I often like to pair it with a simple, fresh side. Here are some of my favorite keto-friendly accompaniments:

Steamed Green Beans or Asparagus: A light, crisp green vegetable provides a lovely contrast to the creamy sauce.
Cauliflower Rice: It is the perfect absorbent base for soaking up all that delicious sauce, without the carbs of traditional rice.
Simple Side Salad: A fresh green salad with a light vinaigrette is always a great choice to brighten the meal.
Roasted Broccoli: Roasting brings out the sweetness in broccoli and pairs beautifully with the savory chicken.

Frequently Asked Questions (FAQ)

I know you might have a few questions about making this Keto Mushroom Chicken Casserole, so I am here to help!

Q: How many carbs are in this Keto Mushroom Chicken Casserole? A: I do not provide specific carb counts for my recipes, as they can vary based on exact ingredients and portion sizes. However, this recipe uses naturally low-carb ingredients like chicken, mushrooms, and full-fat dairy, making it excellent for a ketogenic diet.

Q: Can I add other vegetables to the casserole? A: Absolutely! I often add a handful of fresh spinach, wilted into the sauce at the end, or some diced bell peppers or zucchini cooked alongside the mushrooms. Just remember to account for their water content and adjust simmering time if needed.

Q: Are there dairy-free options for this recipe? A: Yes! As mentioned in my “Smart Swaps” section, you can use full-fat coconut cream (the thick part from a can) or homemade cashew cream in place of heavy cream. For the sour cream, unsweetened full-fat coconut yogurt or a dairy-free cashew sour cream alternative works well.

Q: Can I use chicken breasts instead of tenderloins? A: You certainly can! I would recommend cutting boneless, skinless chicken breasts into 1-inch pieces to ensure they cook evenly and quickly, similar to the tenderloins. Adjust searing time as needed to avoid overcooking.

Conclusion

I truly hope this Keto Mushroom Chicken Casserole becomes a beloved staple in your kitchen. I find it to be the perfect answer to the age-old question, “What will I cook?” It is simple, incredibly flavorful, and perfectly aligned with a low-carb lifestyle, making weeknight dinners easy and enjoyable again. I promise you, the creamy sauce, tender chicken, and earthy mushrooms are a winning combination you will want to make again and again.

I would love to hear from you! Please leave a comment below if you try this recipe, share your cooking results, or offer your own tips and variations. Your feedback always makes my day. Happy cooking!