Keto Garlic Mushroom Chicken Casserole – Creamy, Easy & Low-Carb!

Keto Garlic Mushroom Chicken Casserole. You know those nights when you want something creamy and cozy, but you also want to keep it low carb and not fuss over a dozen steps? This recipe has become my answer to that exact mood. The chicken gets juicy, the mushrooms soak up garlicky butter, and the sauce turns velvety without being heavy. It is a one-pan kind of magic that hits the table fast and disappears even faster. If you have picky eaters, this one usually wins them over, too.

Essential Ingredients for a Creamy Keto Casserole

For a satisfying pan of comfort, you just need a handful of real ingredients that do the heavy lifting. This Keto Garlic Mushroom Chicken Casserole is simple to shop for and easy to prep. Here is what you will need and why it matters.

• Chicken: boneless skinless thighs for richness or breasts for a leaner bite
• Mushrooms: baby bella or cremini for meaty flavor, sliced
• Fresh garlic: lots of it, minced
• Onion or shallot: finely diced for sweetness and depth
• Butter and olive oil: for searing and flavor
• Heavy cream and cream cheese: the creamy base
• Parmesan: freshly grated, helps thicken and adds a salty finish
• Chicken bone broth: builds body without carbs
• Dijon mustard: a tiny spoon for brightness
• White wine: optional, but amazing for deglazing
• Fresh thyme or parsley: for a clean herbal finish
• Shredded mozzarella: for that golden, bubbly top
• Xanthan gum: optional pinch if you want extra thickness
• Salt, pepper, and a pinch of red pepper flakes: to balance everything

For more creamy garlic inspiration, peek at this easy creamy garlic parmesan chicken. It hits similar flavors in skillet form.

Choosing Your Protein: Chicken Thighs vs. Chicken Breasts

Thighs are my pick when I want a guarantee of juicy results. They stay tender even if you cook them a minute or two longer. Breasts are great if you prefer lean, but watch the temp closely so they do not dry out. Either way, cut the chicken into medium chunks for even cooking and more browned edges.

The Best Mushrooms for Maximum Flavor (Baby Bella, Cremini, and More)

Baby bella and cremini are superstars for casseroles. They have more flavor than white button mushrooms and a meatier texture. Slice them medium thick so they do not vanish into the sauce. If you love mushrooms, you can mix in a few shiitakes for an earthy edge.

Keto-Friendly Aromatics: Fresh Garlic, Onions, and Herbs

Fresh garlic is the backbone here. Mince it fine and add it after the mushrooms soften so it does not scorch. A little onion or shallot adds sweetness and body, while herbs like thyme, rosemary, or parsley keep the sauce lively. Finish with fresh parsley for a bright, green pop on top.

The Secret to the Perfect Low-Carb Creamy Garlic Sauce

This sauce leans on high-fat dairy for silkiness and natural thickeners for body. It is indulgent without needing flour. The key is a gentle simmer and patience while the sauce tightens up.

Mastering the High-Fat Base: Heavy Cream, Butter, and Cream Cheese

Start by letting butter melt into the cooked mushrooms and onions. Pour in heavy cream and add a small scoop of cream cheese. Stir slowly while it melts. The cream cheese binds the sauce, the butter adds richness, and the cream makes it all silky. Keep the heat medium low and do not boil or it can split.

Natural Thickeners: Using Parmesan Cheese and Xanthan Gum

Freshly grated Parmesan thickens as it melts and adds nutty, salty flavor. Sprinkle it in gradually and stir well. If you want a thicker sauce without extra carbs, a tiny pinch of xanthan gum goes a long way. Sprinkle over the surface and whisk to avoid clumps. Remember, a little is plenty.

Adding depth with white wine, Dijon, or chicken bone broth: Deglaze the pan with a splash of dry white wine after searing to lift those tasty browned bits. If you do not use wine, bone broth works wonderfully. A teaspoon of Dijon mustard brightens the richness so every bite stays balanced.

Step-by-Step Instructions: How to Make This One-Pan Casserole

1. Sear the chicken. Pat chicken dry, season with salt, pepper, and pepper flakes. Heat olive oil in a large oven-safe skillet over medium high. Sear chicken until golden on both sides. Remove to a plate. This step builds flavor and keeps your Keto Garlic Mushroom Chicken Casserole juicy.

2. Sauté the mushrooms and aromatics. Add butter to the skillet, then mushrooms. Let them brown without stirring too much so they do not steam. Add onion until soft, then garlic until fragrant, about 30 seconds. Season lightly with salt and thyme.

3. Deglaze the skillet. Pour in white wine or a splash of broth. Scrape up browned bits with a wooden spoon. That is pure flavor going into your sauce.

4. Build the sauce. Stir in bone broth, heavy cream, and cream cheese. Simmer gently until smooth. Sprinkle in Parmesan and whisk until lightly thickened. Taste and adjust with salt, pepper, and a dab of Dijon if you like.

5. Assemble. Nestle chicken back into the pan with the sauce and mushrooms. Sprinkle mozzarella and a bit more Parmesan over the top.

6. Bake. Transfer to a 375°F oven and bake 12 to 15 minutes, until the chicken reaches 165°F in the center and the top is bubbly and golden.

7. Rest and garnish. Let it rest 5 minutes so the sauce settles. Finish with fresh parsley or extra thyme. Serve hot.

If you like learning by category, here is a helpful breakdown of simple chicken casserole basics that pairs nicely with this recipe.

Expert Tips from the Test Kitchen for the Best Results

How to deglaze like a pro. After searing, the brown bits stuck to the pan are flavor gold. Pour in a splash of wine or broth and scrape with a wooden spoon. Keep heat moderate so the liquid reduces without burning.

Hit the ideal internal temperature. For safety and juiciness, chicken should read 165°F in the thickest part. A quick-read thermometer is your best friend here. If using breasts, pull them the moment they hit temp to avoid overcooking.

Get that golden top. For a bakery-window look, position the skillet in the upper third of the oven. If you want extra color, broil for 1 to 2 minutes at the end, watching closely so the cheese does not over-brown.

Craving another bubbly bake when this pan is gone? Try this cheesy favorite next: chicken parmesan casserole. It is a family pleaser.

Recipe Variations and Customizations

Adding low-carb veggies. Stir in a few handfuls of fresh spinach during the sauce step for color and nutrients. Blanched broccoli florets work beautifully. Or build the casserole over a bed of cauliflower rice for a heartier base. If you use cauliflower rice, pre-sauté it to drive off moisture so the sauce stays creamy.

Dairy-free swaps. Try full-fat coconut milk with a little extra Parmesan-style dairy-free cheese or nutritional yeast for depth. Use avocado oil instead of butter. The flavor profile will change a bit, but you still get a lush, cozy bake.

Quick and easy vs flavor-first. For a speed run, skip searing and assemble raw seasoned chicken with sauce and mushrooms, then bake until done. The texture is softer and still tasty. For the best flavor, take the extra 10 minutes to sear and sauté. Browning is where the magic happens.

If you are in a low carb mood this week, you might also like this low carb chicken casserole lineup for more ways to meal plan without the carbs.

Serving Suggestions: What to Pair with Your Keto Chicken Bake

• Low-carb bases: zucchini noodles tossed with olive oil, creamy cauliflower mash, or palmini noodles warmed in butter
• Simple sides: roasted green beans with lemon, a crisp arugula salad with olive oil and vinegar, or garlicky asparagus
• Cozy sips: serve a small bowl of warming chicken mushroom soup as a starter if you want extra comfort

However you plate it, this dish is rich, so keep sides light and bright for balance.

Meal Prep, Storage, and Reheating Guide

How to store leftovers. Let the casserole cool to room temp, then portion into airtight containers. Refrigerate up to 4 days. For freezing, skip the mozzarella topping at first. Freeze the saucy chicken and mushrooms up to 2 months. Thaw overnight in the fridge, then add cheese and bake.

Best reheating methods. Reheat gently at 325°F, covered, until hot, then uncover to re-crisp the cheese. On the stovetop, add a splash of broth or cream and warm low and slow, stirring to keep the sauce smooth. The microwave works in a pinch. Heat in 45 second bursts, stirring in between so the sauce does not split.

If you want more comfort food inspiration for weeknights, this roundup of cozy low carb chicken casserole ideas can keep dinner interesting all month.

Common Questions

Can I use rotisserie chicken? Yes. Skip the sear and start with the sauce. Add pulled rotisserie chicken once the sauce is smooth and bake to heat through. It will be softer but still delicious.

What if I do not cook with wine? Use chicken bone broth with a teaspoon of lemon juice or extra Dijon. You still get brightness without the wine.

How do I prevent a watery casserole? Brown mushrooms well to cook off moisture and simmer the sauce until it lightly coats a spoon before baking. Do not rinse mushrooms under water; wipe them clean.

Can I make this completely ahead? Assemble up to the cheese, cover, and refrigerate up to 24 hours. Add 5 to 10 minutes to the bake time since it is starting cold.

What cheese combo is best? Mozzarella for melt, Parmesan for salty nuttiness. A little Gruyere adds a toasty vibe if you want a twist.

A cozy wrap-up for hungry nights

I reach for this recipe whenever I want something comforting that still feels smart. Keto Garlic Mushroom Chicken Casserole checks every box: creamy, savory, and friendly for weeknights. Start with a hot sear, build a simple sauce, and let the oven finish the job. If you are craving more ideas in this flavor zone, this guide from Creamy Low Carb Goodness! is a great resource to browse. Ready to grab a skillet and make it happen tonight? You have got this.

Print