Keto Garlic Mushroom Chicken Casserole Recipe

Keto Garlic Mushroom Chicken Casserole Recipe tastes rich, creamy, and garlicky with juicy chicken and golden mushrooms in every bite. It works perfectly for busy weeknights or cozy Sunday dinners, since you can get it on the table in about 45 minutes. I first made a version of this on a rainy Tuesday when I refused to wash more than one pan, and it stuck around in my rotation ever since.

Why You Should Try This Keto Garlic Mushroom Chicken Casserole Recipe

This casserole hits that comfort food craving while still staying low carb and keto friendly. You get tender chicken, caramelized mushrooms, and a cheesy, garlicky cream sauce that feels like takeout-level indulgence without the mystery ingredients.

It also works great for meal prep, since it reheats well and pairs with simple sides like cauliflower rice or a green salad. You can scale it up for guests or halve it for a smaller household without much effort.

“This Keto Garlic Mushroom Chicken Casserole Recipe tastes like a cozy restaurant dish in a baking dish, and my whole family licked their plates clean. ★★★★★”

Ingredients You’ll Need

Chicken and Vegetables

• 2 pounds boneless skinless chicken thighs, cut into bite-size pieces
  • Use thighs for juicier results; use chicken breasts if you prefer leaner meat and shorten cook time slightly.
• 16 ounces cremini or baby bella mushrooms, sliced
  • White button mushrooms also work, but cremini bring deeper flavor.
• 1 small yellow onion, finely diced
• 4 to 6 cloves garlic, minced
• 2 tablespoons fresh parsley, chopped, plus more for garnish
• 1 teaspoon fresh thyme leaves or 1/2 teaspoon dried thyme

Fats and Dairy

• 3 tablespoons butter
  • Use salted butter and reduce added salt slightly, or use unsalted and season to taste.
• 1 tablespoon olive oil or avocado oil
• 1 cup heavy whipping cream
• 4 ounces full-fat cream cheese, softened and cubed
• 1 1/2 cups shredded mozzarella cheese
• 1/2 cup grated Parmesan cheese
  • Use real Parmesan from a wedge if possible; shelf-stable grated cheese works in a pinch.

Seasonings

• 1 teaspoon fine sea salt, plus more to taste
• 1/2 teaspoon black pepper
• 1 teaspoon garlic powder
• 1/2 teaspoon smoked paprika or regular paprika
• 1/4 teaspoon red pepper flakes, optional, for a little heat

Pantry Shortcuts and Substitutions

• Use pre-sliced mushrooms to save time.
• Use jarred minced garlic if you feel tired or rushed, though fresh garlic gives better flavor.
• Use rotisserie chicken (about 4 cups shredded) instead of raw chicken; skip the browning step and stir it into the sauce before baking.
• Replace heavy cream with full-fat canned coconut milk if you avoid dairy; use a dairy free cheese alternative and skip Parmesan for a more strict dairy free version.
• Use Italian seasoning in place of thyme if that already sits in your pantry.

Equipment List

• 1 large oven-safe skillet or sauté pan (12 inch) or a regular skillet plus a 9×13 inch baking dish
• Cutting board and sharp knife
• Wooden spoon or silicone spatula
• Measuring cups and spoons
• Cheese grater if you grate your own cheese
• Aluminum foil (optional, to cover if the top browns too quickly)

Tips & Tricks

• Pat the chicken dry with paper towels so it browns instead of steams.
• Cut chicken pieces roughly the same size so they cook evenly.
• Do not crowd the pan; brown chicken in two batches if needed to get color and flavor.
• Let mushrooms sit in the hot pan without stirring for a minute at a time so they caramelize instead of turning soggy.
• Use room temperature cream cheese so it melts into the sauce without clumps.
• Lower the heat before adding cream and cream cheese so the sauce stays smooth and does not break.
• Taste the sauce before baking and adjust salt, pepper, or garlic powder so the flavor hits just right.
• Broil the casserole for 2 to 3 minutes at the end if you want extra bubbly, browned cheese on top.
• Add a handful of baby spinach or chopped kale to the sauce for extra veggies without extra carbs.
• Let the casserole rest 5 to 10 minutes after baking so the sauce thickens and slices hold together.

How to Make Keto Garlic Mushroom Chicken Casserole Recipe

Step 1: Prep the Ingredients

Preheat your oven to 375°F (190°C).
Grease a 9×13 inch baking dish if you do not use an oven-safe skillet.
Slice mushrooms, dice onion, mince garlic, and cut chicken into bite-size pieces.
Pat the chicken dry and season it with salt, pepper, and smoked paprika.

Step 2: Brown the Chicken

Heat olive oil and 1 tablespoon butter in a large skillet over medium high heat.
Add half the chicken in a single layer and sear it for 3 to 4 minutes per side until it turns golden and mostly cooked through.
Transfer the browned chicken to a plate and repeat with the remaining chicken, adding a bit more oil if the pan looks dry.
Set all the browned chicken aside.

Step 3: Sauté the Vegetables

Lower the heat to medium and add the remaining 2 tablespoons butter to the same skillet.
Add the diced onion and cook for 2 to 3 minutes until it softens and turns translucent.
Add the sliced mushrooms and cook for 6 to 8 minutes, stirring occasionally, until they release their moisture and turn golden around the edges.
Stir in the minced garlic, thyme, garlic powder, and red pepper flakes and cook for 1 minute until fragrant.

Step 4: Build the Creamy Garlic Mushroom Sauce

Pour in the heavy cream and stir, scraping up any browned bits from the bottom of the pan.
Add the cream cheese cubes and stir frequently over medium low heat until the cream cheese melts and the sauce turns smooth.
Stir in half of the Parmesan and half of the mozzarella until they melt into the sauce.
Taste and adjust seasoning with more salt and pepper if needed.

Step 5: Combine Chicken and Sauce

Add the browned chicken and any juices from the plate into the skillet with the sauce.
Stir to coat every piece of chicken in the creamy garlic mushroom sauce.
Fold in the chopped parsley.
If you use a separate baking dish, transfer the mixture into the greased 9×13 inch dish and spread it into an even layer.

Step 6: Top with Cheese

Sprinkle the remaining mozzarella and Parmesan evenly over the top of the casserole.
Make sure the cheese reaches the edges so every scoop gets a cheesy crust.
If you like extra color, dust a pinch of paprika over the top.

Step 7: Bake

Place the skillet or baking dish in the preheated oven.
Bake for 18 to 22 minutes until the casserole bubbles around the edges and the cheese melts and turns lightly golden.
If you want a deeper golden top, switch the oven to broil for 2 to 3 minutes, watching closely so the cheese does not burn.
Remove from the oven and let it rest for 5 to 10 minutes before serving.

Step 8: Garnish and Serve

Sprinkle extra chopped parsley over the top for a fresh pop of color.
Scoop the Keto Garlic Mushroom Chicken Casserole Recipe into bowls or onto plates.
Serve it hot with your favorite low carb sides.
Enjoy the leftovers for lunch and feel slightly smug that you already cooked.

What to Serve with Keto Garlic Mushroom Chicken Casserole Recipe

This Keto Garlic Mushroom Chicken Casserole Recipe pairs nicely with cauliflower rice, which soaks up the creamy garlic sauce like a champ. You can also serve it with roasted broccoli, green beans, or a simple side salad with a light vinaigrette. If you crave something cozy, spoon it over mashed cauliflower or sautéed shredded cabbage. A chilled glass of sparkling water with lemon or a flavored seltzer rounds out the meal without adding sugar.

Storage Options

• Store leftovers in an airtight container in the fridge for up to 4 days.
• Reheat single portions in the microwave in 45 to 60 second bursts, stirring between bursts, until hot and creamy.
• Reheat larger portions in a covered baking dish at 325°F (165°C) for 15 to 20 minutes until warmed through.
• Freeze cooled portions in freezer safe containers for up to 2 months, then thaw overnight in the fridge before reheating.
• Add a splash of cream or a small knob of butter when reheating if the sauce looks too thick.

Keto Garlic Mushroom Chicken Casserole Recipe

Keto Garlic Mushroom Chicken Casserole is a rich, creamy, garlicky bake with juicy chicken and golden mushrooms, perfect for busy weeknights or cozy dinners in about 45 minutes.

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Prep Time 15 minutes mins

Cook Time 30 minutes mins

Total Time 45 minutes mins

Servings: 6

Course: Chicken

Ingredients

  

• 2 pounds boneless skinless chicken thighs, cut into bite-size pieces
• 16 ounces cremini or baby bella mushrooms, sliced
• 1 small yellow onion, finely diced
• 4–6 cloves garlic, minced
• 2 tablespoons fresh parsley, chopped, plus more for garnish
• 1 teaspoon fresh thyme leaves or 1/2 teaspoon dried thyme

• 3 tablespoons butter
• 1 tablespoon olive oil or avocado oil
• 1 cup heavy whipping cream
• 4 ounces full-fat cream cheese, softened and cubed
• 1 1/2 cups shredded mozzarella cheese
• 1/2 cup grated Parmesan cheese

• 1 teaspoon fine sea salt, plus more to taste
• 1/2 teaspoon black pepper
• 1 teaspoon garlic powder
• 1/2 teaspoon smoked paprika or regular paprika
• 1/4 teaspoon red pepper flakes

Instructions

 

1. Preheat the oven to 375°F (190°C). If not using an oven-safe skillet, lightly grease a 9x13 inch baking dish.
2. Slice the mushrooms, dice the onion, mince the garlic, and cut the chicken into bite-size pieces.
3. Pat the chicken dry with paper towels, then season with salt, pepper, and smoked paprika.

1. Heat the olive oil and 1 tablespoon of the butter in a large skillet over medium-high heat.
2. Add about half of the chicken in a single layer and sear for 3–4 minutes per side, until golden and mostly cooked through. Transfer to a plate.
3. Repeat with the remaining chicken, adding a bit more oil if needed. Set all browned chicken aside.

1. Reduce the heat to medium and add the remaining 2 tablespoons butter to the same skillet.
2. Add the diced onion and cook for 2–3 minutes until softened and translucent.
3. Add the sliced mushrooms and cook for 6–8 minutes, stirring occasionally, until they release their moisture and turn golden around the edges.
4. Stir in the minced garlic, thyme, garlic powder, and red pepper flakes (if using), and cook for about 1 minute until fragrant.

1. Pour in the heavy whipping cream and stir, scraping up any browned bits from the bottom of the pan.
2. Add the cubed cream cheese and cook over medium-low heat, stirring frequently, until the cream cheese melts and the sauce is smooth.
3. Stir in half of the Parmesan and half of the mozzarella until melted and incorporated.
4. Taste and adjust seasoning with additional salt and pepper if needed.

1. Add the browned chicken and any accumulated juices back into the skillet and stir to coat in the creamy garlic mushroom sauce.
2. Fold in the chopped parsley. If using a separate baking dish, transfer the mixture to the prepared 9x13 inch dish and spread into an even layer.
3. Sprinkle the remaining mozzarella and Parmesan evenly over the top of the casserole.
4. Bake for 18–22 minutes, until the casserole is bubbling around the edges and the cheese is melted and lightly golden. For a deeper golden top, broil for 2–3 minutes, watching closely.
5. Remove from the oven and let the casserole rest for 5–10 minutes before serving. Garnish with extra chopped parsley if desired.

Notes

Nutrition Information
Approximate per serving (6 servings): 520 calories; fat 40 g; saturated fat 20 g; carbohydrates 8 g; fiber 1 g; sugars 3 g; protein 34 g; sodium 750 mg. Values are estimates and will vary based on specific ingredient brands and exact portion sizes.