Ultra-Creamy Keto Chicken Alfredo Casserole (High-Protein, Easy Meal Prep)

Rich, velvety Alfredo sauce, tender juicy chicken, and perfectly tender-crisp broccoli florets come together in this deeply satisfying Keto Chicken Alfredo Casserole. Traditional casseroles rely heavily on heavy pasta, but this low-carb version swaps the noodles for roasted broccoli to deliver all the cozy, indulgent comfort with a fraction of the carbs. Packed with high-quality protein and healthy fats, it's a quick 35-minute weeknight dinner that reheats remarkably well for make-ahead work lunches.

Prep Time 15 Mins

Cook Time 20 Mins

Total Time 35 Mins

Servings 6 Servings

Net Carbs 5g

Why This Low-Carb Casserole Works

• No Watery Sauce: Pre-steaming and thoroughly drying the broccoli prevents excess moisture from diluting your rich garlic-parmesan cream sauce.
• Real Cream Cheese Emulsifier: Cream cheese stabilizes the heavy cream and fresh parmesan, preventing the sauce from breaking or separating during baking.
• High-Protein Fuel: Using pre-cooked, seasoned chicken breast delivers 38 grams of protein per serving, keeping you full for hours. If you love quick protein prep, try pairing dinner rotation days with our crispy air fryer chicken bites.
• Meal Prep Ready: Holds up crisp and creamy in glass food prep containers for up to 4 days in the fridge without losing structure.

Ingredients You'll Need

• Chicken Breast: 3 cups cooked chicken breast, shredded or diced (rotisserie chicken works exceptionally well here).
• Broccoli Florets: 5 cups fresh broccoli florets, cut into bite-sized pieces.
• Butter: 2 tablespoons unsalted butter.
• Garlic: 4 cloves fresh garlic, minced.
• Heavy Whipping Cream: 1 cup heavy cream for a silky, full-fat base.
• Cream Cheese: 4 oz plain cream cheese, softened to room temperature.
• Parmesan Cheese: 1 cup freshly grated Parmesan cheese (avoid pre-shredded canned parmesan for smooth melting).
• Mozzarella Cheese: 1 cup shredded low-moisture mozzarella cheese for that perfect bubbly brown top.
• Seasonings: 1 tsp Italian seasoning, 1/2 tsp garlic powder, 1/2 tsp kosher salt, 1/4 tsp cracked black pepper, 1/4 tsp red pepper flakes (optional).

Equipment Needed

• 9x13-inch ceramic or glass baking dish
• Large skillet or saucepan for sauce
• Whisk and spatula
• Colander and paper towels

Step-by-Step Instructions

1. Preheat & Prep Dish: Preheat your oven to 375°F (190°C). Lightly grease a 9x13-inch baking dish with olive oil or cooking spray.
2. Blanch the Broccoli: Place broccoli florets into a microwave-safe bowl with 2 tablespoons of water. Cover and microwave on HIGH for 2.5 to 3 minutes until bright green and tender-crisp. Drain completely in a colander and pat thoroughly dry with paper towels to eliminate surplus moisture.
3. Build the Garlic Alfredo Sauce: Melt butter in a large skillet over medium heat. Add minced garlic and cook for 60 seconds until fragrant. Reduce heat to low, add softened cream cheese, and whisk until smooth. Pour in heavy whipping cream, Italian seasoning, garlic powder, salt, and pepper. Simmer for 3 minutes until gently bubbling.
4. Melt Cheese in Sauce: Remove the skillet from heat. Whisk in 3/4 cup of the grated Parmesan cheese until fully melted and silky.
5. Combine Ingredients: Add the dried broccoli florets and shredded chicken breast directly into the skillet with the Alfredo sauce. Toss until everything is evenly coated in sauce.
6. Assemble Casserole: Transfer the chicken and broccoli mix into your prepared baking dish. Spread evenly. Top with shredded mozzarella and the remaining 1/4 cup Parmesan cheese.
7. Bake to Bubbly Perfection: Bake uncovered at 375°F for 18–20 minutes until the cheese is completely melted and bubbling at the edges. Broil on HIGH for 2 minutes at the end for a golden brown cheese crust. Let sit 5 minutes before serving.

Pro Cooking Tips

Avoiding Watery Keto Casseroles:

Crucial step: never skip drying your steam-cooked broccoli! Water trapped in vegetable florets releases into the heavy cream during baking and separates your sauce. Press the florets gently between clean kitchen towels before folding into the Alfredo.

Substitutions & Variations

• Veggie Swaps: Swap or mix broccoli with steamed cauliflower florets or fresh baby spinach (squeezed dry).
• Add Bacon: Stir in 1/2 cup of crispy crumbled bacon bits into the sauce for a Bacon Chicken Alfredo variation.
• Protein Alternative: Leftover roasted turkey breast or garlic butter shrimp work wonderfully in place of chicken breast. For beef lovers, check out our high-protein garlic butter steak bites for another low-carb dinner idea.

Meal Prep, Storage & Reheating

This recipe is exceptional for high-protein lunchbox prep and weekday meal planning.

• Refrigeration: Allow the casserole to cool completely. Divide into airtight meal prep glass containers. Refrigerate for up to 4 days.
• Reheating at Work or Home: Microwave individual lunch portions covered loosely on 70% power for 1.5 to 2 minutes. Lower heat prevents the rich dairy fat from separating. Alternatively, reheat in a 350°F oven for 10 minutes until warm.
• Freezing Advice: Cream sauce dishes can alter texture when frozen and thawed. While safe to freeze for up to 2 months, fresh preparation or standard fridge meal-prep yields the best creamy texture.

Frequently Asked Questions

Can I use rotisserie chicken for this casserole?

Yes! Rotisserie chicken is a fantastic timesaver. Shred both breast and thigh meat for added moisture and quick prep.

Why did my Alfredo sauce split during baking?

Sauce splits when exposed to high heat without an emulsifier or when too much liquid is present. Cream cheese acts as a natural emulsifier, and thoroughly drying the broccoli protects the sauce consistency.

How do I pack this for a hot work lunchbox?

Reheat your portion thoroughly in the morning, then pack it directly into an insulated wide-mouth food flask/thermos pre-warmed with hot water. It stays hot until lunchtime without requiring a microwave.

Is this casserole suitable for strict keto?

Yes, with only 5 grams of net carbs per generous serving and healthy fats from heavy cream and butter, it fits perfectly within standard daily keto macro goals.

Keto Chicken Alfredo Casserole

Fit Fork Recipes • Serves 6

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Ingredients

• 3 cups cooked chicken breast, shredded
• 5 cups fresh broccoli florets
• 2 tbsp unsalted butter
• 4 cloves garlic, minced
• 1 cup heavy whipping cream
• 4 oz cream cheese, softened
• 1 cup freshly grated Parmesan cheese, divided
• 1 cup shredded low-moisture mozzarella cheese
• 1 tsp Italian seasoning
• 1/2 tsp garlic powder
• 1/2 tsp kosher salt
• 1/4 tsp cracked black pepper

Instructions Summary

1. Preheat oven to 375°F (190°C). Grease 9x13 dish.
2. Steam broccoli 3 mins; drain and pat thoroughly dry.
3. Sauté garlic in butter; whisk in cream cheese, heavy cream, and seasonings.
4. Stir in 3/4 cup Parmesan until smooth.
5. Fold chicken and broccoli into sauce; transfer to dish.
6. Top with mozzarella and 1/4 cup Parmesan.
7. Bake 18-20 mins until bubbly and golden top.

Nutrition Facts (Per Serving)

Calories
440 kcal

Protein
38g

Fat
29g

Total Carbs
7g

Fiber
2g

Net Carbs
5g

Sodium
580mg

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