Keto Garlic Mushroom Chicken Casserole Recipe tastes rich, creamy, garlicky, and cozy, with juicy chicken and tender mushrooms tucked into a cheesy low carb sauce. It works perfectly for busy weeknights or casual entertaining, since you pull it together in about 45 minutes total. I test this one so often that my family now calls it “the casserole,” which feels like the highest compliment in my house.
Why Keto Garlic Mushroom Chicken Casserole Recipe Is Worth It
This casserole hits that comfort food craving without kicking you out of ketosis. You get savory garlic, browned mushrooms, and juicy chicken in a creamy, cheesy sauce that feels like a hug in a baking dish.
It uses simple ingredients you probably keep on hand, so you skip any fancy specialty products. You also cook everything in one skillet and one baking dish, which keeps dishes under control and weeknights sane.
“So much flavor, so few carbs, and my kids actually asked for seconds of mushrooms ★★★★★”
Ingredients You Need
Main Ingredients
- 1.5 to 2 pounds boneless skinless chicken thighs
- Use thighs for juicier results; chicken breast works too, but watch the cook time so it stays tender.
- 2 tablespoons avocado oil or light olive oil
- 8 ounces cremini or baby bella mushrooms, sliced
- White button mushrooms work fine; cremini give deeper flavor.
- 4 to 5 cloves garlic, minced
- 1 small yellow onion, finely diced
- 1 cup heavy whipping cream
- Use full fat; it thickens better and keeps carbs low.
- 4 ounces full fat cream cheese, softened and cubed
- 1 cup shredded mozzarella cheese
- 1/2 cup grated Parmesan cheese
- 1/2 cup chicken broth, low sodium
- 1 teaspoon Dijon mustard
- 1 teaspoon Italian seasoning
- 1/2 teaspoon smoked paprika
- 1/2 teaspoon sea salt, plus more to taste
- 1/2 teaspoon black pepper
- 1 tablespoon fresh parsley, chopped, for garnish
Pantry Shortcuts & Notes
- Use pre sliced mushrooms to save prep time.
- Use jarred minced garlic if you feel tired or rushed, though fresh garlic gives brighter flavor.
- Use pre shredded cheese from a brand that skips starches when possible; if not, you still keep carbs low, just slightly higher.
- Use rotisserie chicken as a shortcut; shred about 3 cups and skip the browning step.
Optional Add Ins
- 1 cup chopped fresh spinach or kale
- 1/4 teaspoon red pepper flakes for gentle heat
- 1/4 teaspoon dried thyme for extra herby flavor
Equipment List
- Large oven safe skillet or sauté pan
- If your skillet does not go in the oven, use a regular skillet plus a 9 by 13 inch baking dish.
- Cutting board and sharp knife
- Measuring cups and spoons
- Wooden spoon or silicone spatula
- Mixing bowl, optional, if you prefer to mix cheeses separately
- Aluminum foil, optional, to cover if the top browns too quickly
Quick Tips & substitutions
- Brown the chicken in batches so it sears nicely and does not steam.
- Slice mushrooms evenly so they cook at the same rate and do not turn soggy.
- Use chicken breast instead of thighs, but reduce the initial sear time by 1 to 2 minutes per side.
- Swap heavy cream with full fat coconut cream for a dairy light version, then use dairy free cheese.
- Use ghee instead of oil for richer flavor and a buttery note.
- Add a handful of spinach at the end of the stovetop step so it wilts into the sauce.
- Keep the sauce slightly loose before baking, since it thickens in the oven.
- Taste the sauce before baking and adjust salt and pepper so the final dish sings.
How to Make Keto Garlic Mushroom Chicken Casserole Recipe
Step 1: Prep and preheat
Preheat your oven to 375°F. Pat the chicken dry with paper towels and cut large pieces into even sized chunks or strips so they cook evenly. Season both sides with salt, pepper, and half the smoked paprika.
Slice the mushrooms, dice the onion, and mince the garlic. Cube the cream cheese so it melts faster in the sauce. Keep all ingredients close to the stove so you move quickly.
Step 2: Brown the chicken
Heat the avocado oil in a large skillet over medium high heat. Add the chicken in a single layer and sear 3 to 4 minutes per side until it turns golden and cooks almost through. Work in two batches if needed so the pan does not crowd.
Transfer the browned chicken to a plate and keep it nearby. Do not wipe the skillet; keep those browned bits, since they add flavor to the sauce. Lower the heat to medium.
Step 3: Sauté mushrooms, onion, and garlic
Add the sliced mushrooms and onion to the same skillet. Cook 5 to 7 minutes, stirring occasionally, until the mushrooms release their moisture and the edges turn golden. Sprinkle in a pinch of salt to help them soften.
Add the minced garlic and cook 30 to 60 seconds until it smells fragrant. Stir in the Italian seasoning and remaining smoked paprika. Scrape the bottom of the pan to pull up any browned bits.
Step 4: Build the creamy keto sauce
Pour in the chicken broth and stir well. Let it simmer 2 to 3 minutes so it reduces slightly. Add the heavy cream and Dijon mustard and stir until the mixture looks smooth.
Add the cream cheese cubes and stir until they melt into the sauce and turn it thick and velvety. If the cream cheese resists, lower the heat and keep stirring; it always gives in eventually. Taste and adjust salt and pepper.
Step 5: Add chicken and cheeses
Return the browned chicken and any juices from the plate to the skillet. Stir so the chicken nestles into the mushroom garlic cream sauce. If the sauce looks very thick, splash in a bit more broth or cream.
Sprinkle the mozzarella and half the Parmesan evenly over the top. If your skillet is not oven safe, transfer everything to a greased 9 by 13 inch baking dish, then top with cheese there. Sprinkle the remaining Parmesan over the top for extra golden crunch.
Step 6: Bake until bubbly
Place the skillet or baking dish in the preheated oven. Bake 15 to 20 minutes until the cheese melts, the edges bubble, and the chicken reaches 165°F inside. If the top browns too quickly, tent loosely with foil.
Remove from the oven and let the casserole rest 5 to 10 minutes so the sauce thickens slightly. Sprinkle with chopped fresh parsley. Take in that cheesy, garlicky aroma for a second, then serve.
Recipe Variations
- Gluten free: This recipe already avoids gluten; just confirm your broth and Dijon mustard use gluten free brands.
- Extra low carb: Use a bit less onion and more mushrooms to shave off a few carbs.
- Dairy light: Use coconut cream, dairy free cream cheese, and dairy free shredded cheese, then season generously.
- Veggie loaded: Stir in spinach, kale, or chopped broccoli florets before baking.
- Spicy: Add red pepper flakes or a pinch of cayenne to the sauce.
- Extra cheesy: Add shredded cheddar along with mozzarella for a sharper flavor.
- Rotisserie shortcut: Use 3 cups shredded rotisserie chicken and skip the browning step.
Ways to Serve Keto Garlic Mushroom Chicken Casserole Recipe
- Spoon over steamed cauliflower rice or mashed cauliflower for a full keto dinner.
- Serve with roasted green beans, asparagus, or Brussels sprouts on the side.
- Pair with a simple green salad with olive oil and lemon juice.
- Scoop into lettuce cups for a fun handheld option.
- Serve with zucchini noodles or shirataki noodles for a pasta style plate without the carbs.
Storage Success
Let the Keto Garlic Mushroom Chicken Casserole Recipe cool to room temperature, then store leftovers in airtight containers in the fridge for up to 3 to 4 days. Reheat portions gently on the stovetop over low heat or in the oven at 325°F so the sauce stays creamy and the cheese does not turn rubbery. Add a splash of cream or broth while reheating if the sauce looks too thick. Freeze individual portions for up to 2 months, then thaw in the fridge overnight before reheating.
Keto Garlic Mushroom Chicken Casserole Recipe
Ingredients
Method
- Preheat the oven to 375°F (190°C). Pat the chicken dry with paper towels and cut any large pieces into even-sized chunks or strips. Season both sides of the chicken with sea salt, black pepper, and half of the smoked paprika.
- Slice the mushrooms, finely dice the onion, and mince the garlic. Cube the cream cheese so it melts more easily. Set all ingredients near the stove so you can work efficiently.
- Heat the avocado oil in a large oven-safe skillet over medium-high heat. Add the chicken in a single layer and sear for 3 to 4 minutes per side, until golden and almost cooked through. Work in batches if needed to avoid crowding the pan.
- Transfer the browned chicken to a plate and set aside. Do not wipe out the skillet; leave the browned bits in the pan for extra flavor. Reduce the heat to medium.
- Add the sliced mushrooms and diced onion to the same skillet. Cook for 5 to 7 minutes, stirring occasionally, until the mushrooms release their moisture and begin to turn golden at the edges. Season with a pinch of salt.
- Stir in the minced garlic and cook for 30 to 60 seconds, just until fragrant. Add the Italian seasoning and remaining smoked paprika, scraping the bottom of the pan to loosen any browned bits.
- Pour in the chicken broth and stir well, simmering for 2 to 3 minutes to reduce slightly. Add the heavy whipping cream and Dijon mustard, stirring until the mixture is smooth.
- Add the cubed cream cheese and stir until fully melted and the sauce is thick and velvety. If needed, lower the heat and continue stirring until the cream cheese incorporates. Taste and adjust salt and pepper as needed. If using spinach, kale, red pepper flakes, or dried thyme, stir them in now.
- Return the browned chicken and any accumulated juices to the skillet, stirring to coat and nestle the chicken into the mushroom garlic cream sauce. If the sauce seems very thick, add a splash more broth or cream to keep it slightly loose.
- Sprinkle the mozzarella cheese and half of the Parmesan evenly over the top. If your skillet is not oven-safe, transfer everything to a greased 9x13 inch baking dish first, then add the cheeses. Top with the remaining Parmesan for extra golden crunch.
- Place the skillet or baking dish in the preheated oven and bake for 15 to 20 minutes, until the cheese is melted, the edges are bubbling, and the chicken reaches an internal temperature of 165°F (74°C). Tent loosely with foil if the top is browning too quickly.
- Remove from the oven and let the casserole rest for 5 to 10 minutes to allow the sauce to thicken slightly. Garnish with chopped fresh parsley and serve warm.
Notes
Approximate per serving (6 servings): 460 calories; fat 35 g; saturated fat 17 g; carbohydrates 6 g; fiber 1 g; sugars 3 g; protein 30 g; sodium 520 mg. Values are estimates and will vary based on specific ingredients, brands, and any optional add-ins or substitutions.