Creamy Low Carb Chicken Casserole

The smell of thyme and bubbling cheese takes me back to a rainy Tuesday when I accidentally created this casserole while trying to use up leftover chicken and vegetables from my crisper drawer. Sometimes the best recipes happen when you are just trying to avoid grocery shopping for one more day.

I served this to my sister who was doing keto and watched her eyes widen at the first bite. She asked three times if I was sure this was actually low carb before going back for seconds and taking the remaining portion home.

Ingredients

• Boneless skinless chicken breasts: Cutting into bite sized pieces helps them cook faster and absorb more of that creamy sauce flavor
• Broccoli florets: Fresh broccoli holds up better during baking than frozen and adds a lovely texture contrast
• Sliced mushrooms: They release moisture as they cook which blends perfectly with the cream sauce
• Diced onion and minced garlic: The aromatic foundation that makes your kitchen smell amazing while cooking
• Heavy cream: The base of our luxuriously rich sauce without needing any thickeners or flour
• Mozzarella and parmesan cheese: These two cheeses create the perfect balance of melt and sharp savory flavor
• Cream cheese: Adds extra body and tanginess to the sauce making it feel decadent
• Chicken broth: Thin out the cream slightly and add depth of flavor without adding carbs
• Dried thyme: Earthy and aromatic thyme pairs beautifully with both chicken and creamy sauces
• Salt and pepper: Essential seasoning that brings all the flavors together

Instructions

Prep your oven and pan:

Preheat oven to 200°C 400°F and grease a casserole dish with butter or oil

Sauté the aromatics:

Heat olive oil in a large skillet over medium heat then cook onions and garlic for 2–3 minutes until fragrant and translucent

Brown the chicken:

Add chicken pieces to the skillet and cook for 5–6 minutes until golden on the outside but not completely cooked through

Add vegetables:

Toss in mushrooms and broccoli florets and sauté for another 3–4 minutes until they begin to soften then remove from heat

Make the creamy sauce:

In a saucepan combine heavy cream chicken broth cream cheese dried thyme salt and pepper heating gently while stirring until smooth

Melt in the cheeses:

Stir in mozzarella and parmesan cheese until fully melted and the sauce has thickened nicely about 2–3 minutes

Combine everything:

Mix the chicken and vegetables with the creamy sauce in a large bowl until everything is well coated

Assemble the casserole:

Transfer mixture to your prepared casserole dish and sprinkle extra mozzarella on top if desired

Bake to perfection:

Bake for 20–25 minutes until the sauce is bubbly and the cheese on top has turned golden brown

Garnish and serve:

Sprinkle fresh chopped parsley over the top for a pop of color before serving hot

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This recipe has become my go to when friends announce they are starting a low carb diet because it proves that healthy eating does not mean sacrificing comfort or flavor.

Make It Ahead

You can assemble the entire casserole up to 24 hours in advance and keep it covered in the refrigerator. Just add a few extra minutes to the baking time since it will be cold going into the oven.

Storage Suggestions

Store leftovers in an airtight container in the refrigerator for up to 4 days. The sauce actually thickens and flavors meld even more after a day making leftovers arguably better than the first night.

Serving Ideas

A crisp green salad with a lemon vinaigrette cuts through the richness beautifully. For a complete low carb meal serve with roasted cauliflower or steamed green beans.

• A dry white wine like Sauvignon Blanc pairs wonderfully with the creamy sauce
• If not strictly low carb crusty bread is perfect for soaking up extra sauce
• Fresh berries make a light refreshing dessert after this rich meal

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There is something deeply satisfying about a casserole that feels indulgent yet fits your health goals. This one has earned a permanent spot in my regular dinner rotation.

Recipe FAQs

→ Can I make this ahead of time?

Absolutely. Assemble the dish completely, cover tightly, and refrigerate for up to 24 hours before baking. Add 5-10 minutes to the baking time if baking cold from the refrigerator.

→ What vegetables work best as substitutions?

Cauliflower florets, fresh spinach, or zucchini chunks all work beautifully. Add heartier vegetables like cauliflower earlier in the cooking process, while spinach should be stirred in just before baking.

→ Can I freeze this dish?

Yes, freeze before baking for best results. Wrap the assembled casserole tightly in plastic and foil for up to 3 months. Thaw overnight in the refrigerator before baking as directed.

→ How do I know when it's done baking?

The dish is ready when the sauce is bubbling around the edges, the cheese topping has turned golden brown, and a knife inserted into the center comes out hot. The chicken should reach an internal temperature of 165°F.

→ Can I use leftover cooked chicken?

Certainly. Rotisserie chicken or leftover cooked breast works perfectly. Skip the initial browning step, reduce the cooking time by 5-10 minutes, and add the cooked chicken when combining with the sauce.

→ How can I make the sauce thicker?

Let the sauce simmer an extra 2-3 minutes before combining, or add a tablespoon of shredded cheese at a time until reaching your desired consistency. The sauce will also thicken naturally during baking.