Keto Garlic Mushroom Chicken Casserole Recipe tastes rich, creamy, and garlicky with juicy chicken and tender mushrooms tucked into every bite. It uses simple, budget-friendly ingredients that you probably already keep in your fridge and pantry, and it works perfectly for busy weeknights since it takes about 45 minutes from start to finish. I make this when my own family wants comfort food that still fits a low carb lifestyle and does not wreck anyone’s blood sugar.
Reasons To Try This Keto Garlic Mushroom Chicken Casserole Recipe
This casserole delivers cozy comfort with serious flavor from garlic, mushrooms, and a cheesy, creamy sauce that stays low carb. You get all the satisfaction of classic chicken and rice bakes, just without the rice and heavy starch.
It also stretches a pound or two of chicken into several hearty servings, which helps your grocery budget. You can prep it ahead, bake it when you need it, and feed picky kids and keto adults at the same table without cooking two different dinners.
“This Keto Garlic Mushroom Chicken Casserole Recipe tastes like a fancy restaurant dish but comes together with weeknight effort and totally satisfies my low carb cravings. ★★★★★”
Ingredients You Need
Chicken and vegetables
- 1.5 to 2 pounds boneless skinless chicken thighs, cut in bite size pieces
- Thighs stay juicy and forgiving; use chicken breast if you prefer leaner meat, just avoid overcooking.
- 10 ounces mushrooms, sliced
- Cremini or baby bella mushrooms bring deeper flavor; white button mushrooms work fine on a budget.
- 1 small yellow onion, finely chopped
- 3 to 4 cloves garlic, minced
- 1 small head cauliflower, riced, about 4 cups
- 2 tablespoons fresh parsley, chopped, plus extra for garnish
- 1 tablespoon fresh thyme leaves or 1 teaspoon dried thyme
Fats, liquids, and dairy
- 2 tablespoons olive oil or avocado oil
- 2 tablespoons butter
- 1 cup heavy whipping cream
- 1 cup chicken broth, low sodium
- 4 ounces cream cheese, softened and cubed
- 1.5 cups shredded mozzarella cheese
- 1 cup shredded Parmesan or Asiago cheese
- Pre shredded cheese saves time, but hand shredded cheese melts smoother and avoids added starches.
Seasonings
- 1 teaspoon fine sea salt, plus more to taste
- 1 teaspoon black pepper
- 1 teaspoon smoked paprika or sweet paprika
- 1 teaspoon garlic powder
- 1 teaspoon onion powder
- 1/4 teaspoon crushed red pepper flakes, optional for a little heat
Optional add ins
- 1/2 cup chopped spinach or kale
- 1/4 cup cooked bacon pieces
- 1/4 cup chopped sun dried tomatoes (in oil, drained)
Equipment list
- Large skillet or sauté pan
- Medium saucepan
- 9×13 inch baking dish or similar casserole dish
- Cutting board and sharp knife
- Wooden spoon or spatula
- Whisk
- Measuring cups and spoons
Tips
- Pat the chicken dry so it browns instead of steaming.
- Cut chicken pieces the same size so they cook evenly.
- Slice mushrooms on the thicker side so they stay meaty in the casserole.
- Use room temperature cream cheese so it melts into the sauce without lumps.
- Taste and adjust salt and pepper before you pour the sauce over the casserole.
- Do not overcook the cauliflower rice; keep it slightly firm so it does not turn mushy in the oven.
- Grease the baking dish so the cheesy edges release easily.
- 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
1: Sauté veggies and aromatics
Heat 1 tablespoon oil and 1 tablespoon butter in a large skillet over medium heat. Add the chopped onion and cook until it softens and turns translucent, about 4 to 5 minutes. Stir in the sliced mushrooms and cook until they release their liquid and start to brown, about 6 to 8 minutes. Add the minced garlic and cook 1 minute, just until it smells fragrant and toasty.
2: Cook the chicken
Push the mushrooms and onions to the sides of the skillet. Add the remaining 1 tablespoon oil and the chicken pieces to the center in a single layer. Season with salt, pepper, smoked paprika, garlic powder, and onion powder, then cook, stirring occasionally, until the chicken browns and cooks through, about 7 to 9 minutes. Stir everything together so the chicken picks up the mushroom and garlic flavor.
3: Add cauliflower rice and herbs
Stir the cauliflower rice into the skillet with the chicken and mushrooms. Cook 3 to 4 minutes, just until the cauliflower heats through and softens slightly. Add thyme, parsley, and crushed red pepper flakes if you use them, then taste and adjust seasoning. Turn off the heat.
4: Make the creamy garlic sauce
In a medium saucepan, add the chicken broth and cream cheese cubes. Warm over medium low heat and whisk until the cream cheese melts and the mixture looks smooth. Pour in the heavy cream and keep whisking until the sauce thickens slightly and coats the back of a spoon, about 4 to 5 minutes. Stir in half of the shredded mozzarella and half of the Parmesan until they melt into a silky sauce.
5: Assemble the casserole
Preheat your oven to 375°F and lightly grease a 9×13 inch baking dish. Spread the chicken, mushroom, and cauliflower mixture evenly in the dish. Pour the creamy garlic sauce over the top and gently stir or shake the dish so the sauce seeps through all the nooks. Sprinkle the remaining mozzarella and Parmesan over the surface.
6: Bake until bubbly and golden
Place the casserole in the oven and bake for 20 to 25 minutes, until the cheese on top bubbles and turns golden in spots. If you want deeper browning, switch the oven to broil for 1 to 2 minutes, but watch closely so the cheese does not burn. Remove the casserole and let it rest for 5 to 10 minutes so the sauce thickens and the pieces scoop out neatly. Sprinkle with extra parsley before serving.
Different Ways to Try It
- Gluten free: Use gluten free chicken broth and check labels on shredded cheese for hidden starches.
- Extra low carb: Skip sun dried tomatoes and onions, and increase mushrooms and spinach instead.
- Dairy light: Use half the cheese and swap part of the heavy cream with unsweetened almond milk plus a teaspoon of xanthan gum to thicken.
- No cauliflower: Replace cauliflower rice with chopped steamed broccoli or green beans.
- Extra protein: Stir in cooked bacon, diced ham, or leftover shredded rotisserie chicken.
- Veggie loaded: Add spinach, kale, or zucchini slices to the skillet when you cook the mushrooms.
How to Serve Keto Garlic Mushroom Chicken Casserole
Serve generous scoops of this Keto Garlic Mushroom Chicken Casserole Recipe with a crisp green salad or simple cucumber tomato salad for freshness. Pair it with roasted asparagus, green beans, or a quick pan of garlicky sautéed zucchini. You can also spoon it over a bed of extra cauliflower rice or shredded cabbage for a bigger plate that still stays low carb. For kids or non keto folks, offer some buttered noodles or crusty bread on the side and keep your plate grain free.
Make-Ahead and Storage Success
You can assemble the entire casserole up to 24 hours ahead, cover it tightly, and keep it in the fridge until you want to bake it. Add an extra 5 to 10 minutes to the baking time since it starts cold. Store leftovers in airtight containers in the fridge for up to 4 days, and reheat them in the oven or in a skillet over low heat so the sauce stays creamy. Freeze cooled portions for up to 2 months, then thaw overnight in the fridge and reheat gently with a splash of cream or broth if the sauce looks too thick.
Ingredients
Instructions
- Preheat the oven to 375°F (190°C). Lightly grease a 9x13-inch baking dish.
- Heat the olive oil in a large skillet over medium-high heat. Add the chicken pieces, season with paprika, salt, and pepper, and cook until lightly browned on all sides but not fully cooked through, about 5–7 minutes. Transfer the chicken to the prepared baking dish in an even layer.
- In the same skillet, add the sliced mushrooms and cook over medium heat until they release their moisture and start to brown, about 5 minutes. Stir in the minced garlic and cook for 1 minute until fragrant.
- Reduce the heat to low. Add the heavy cream, cream cheese, chicken broth, thyme, and oregano to the skillet. Stir continuously until the cream cheese melts and the sauce becomes smooth and slightly thickened, 3–5 minutes. Adjust seasoning with additional salt and pepper if needed.
- Pour the garlic mushroom cream sauce evenly over the chicken in the baking dish. Sprinkle the shredded mozzarella and grated Parmesan cheese over the top.
- Bake for 18–22 minutes, or until the chicken is cooked through and the casserole is bubbling and lightly golden on top.
- Remove from the oven and let rest for 5 minutes. Garnish with chopped fresh parsley before serving, if desired.
Notes
Approximate per serving (1/6 of recipe): 420 calories; fat 28 g; saturated fat 14 g; carbohydrates 5 g; fiber 1 g; sugars 2 g; protein 36 g; sodium 520 mg. Values are estimates and will vary based on specific ingredient brands and portion sizes.