This keto chicken casserole dish is a quick dinner idea packed with high-protein chicken, broccoli, and melted cheese for a satisfying low-carb meal. Ready in 30 minutes!

Ingredients

Toggle: Metric / US

Instructions

Step 1

Preheat your oven to 375°F (190°C). While the oven is heating, prepare the chicken and broccoli. Cut the chicken breasts into uniform bite-sized pieces, about 1-inch cubes. This ensures even cooking and a nice texture in every bite. Fresh broccoli should be washed and cut into small florets; if you prefer, you can also use frozen broccoli (thawed and patted dry). The key is to have the broccoli pieces similar in size to the chicken so they cook evenly. Set both aside.

Step 1 image
Step 2

In a large oven-safe skillet (or a regular skillet if you’ll transfer to a baking dish), heat 1 tablespoon of olive oil over medium-high heat. Once the oil shimmers, add the chicken pieces in a single layer. Do not overcrowd the pan; if necessary, cook in batches. Sear the chicken for 3-4 minutes per side until golden brown and cooked through (internal temperature reaches 165°F/74°C). The browning adds flavor through the Maillard reaction. Remove the chicken from the skillet and set aside on a plate. The skillet will have browned bits (fond) that add depth to the sauce.

Step 2 image
Step 3

In the same skillet, reduce the heat to medium. Add the minced garlic and sauté for about 30 seconds until fragrant, being careful not to burn it. Then add the softened cream cheese, heavy cream, and chicken broth. Stir continuously with a wooden spoon or whisk until the cream cheese is fully melted and the sauce is smooth. The mixture should be creamy and slightly thickened. Season with onion powder, salt, black pepper, and red pepper flakes if using. Taste and adjust seasoning. This creamy sauce is the heart of the casserole, providing rich flavor without any noodles.

Step 4

Return the cooked chicken to the skillet, along with the broccoli florets. Stir gently to coat everything evenly with the creamy sauce. The broccoli will still be raw at this point but will cook perfectly in the oven. If your skillet is not oven-safe, transfer the mixture to a greased 9×13-inch baking dish at this point.

Step 5

Top the casserole with the shredded cheddar and mozzarella cheeses, spreading them evenly over the surface. The cheese will create a golden, bubbly crust as it bakes. Sprinkle the grated Parmesan on top for an extra savory, nutty flavor that complements the creamy sauce beautifully.

Step 6

Bake in the preheated oven for 15-20 minutes, until the cheese is melted and bubbly and the broccoli is tender-crisp. If you prefer a deeper golden crust, you can switch the oven to broil for the last 2 minutes, watching closely to prevent burning. The casserole should be bubbling around the edges and the cheese should have a beautiful golden brown color. Remove from the oven and let it rest for 5 minutes before serving. This allows the sauce to set slightly, making it easier to serve.

Step 7

Garnish with fresh chopped parsley for a pop of color and freshness. Serve hot as a complete meal. This casserole is satisfying on its own, but you can also pair it with a side salad or steamed vegetables if desired. Leftovers can be stored in an airtight container in the refrigerator for up to 4 days. Reheat gently in the microwave or oven.

For best results

  • For the best texture, use fresh broccoli instead of frozen. Fresh broccoli retains its crunch and doesn't release excess water that can make the casserole watery. If you must use frozen, thaw it completely and pat it dry with paper towels to remove as much moisture as possible. Overcooked broccoli can become mushy, so aim for tender-crisp after baking.
  • To ensure the chicken stays juicy, avoid overcooking it during the initial sear. Cook just until it reaches 165°F (74°C) internally. The chicken will continue to cook slightly in the oven, so slightly undercooking at the stovetop stage is fine. Use a meat thermometer for accuracy.
  • The cream cheese must be at room temperature to blend smoothly into the sauce. Cold cream cheese will create lumps. Take it out of the refrigerator 30 minutes before starting, or microwave it in 10-second intervals until softened but not melted. This ensures a silky, lump-free sauce.
  • You can customize the cheese blend to your preference. Gruyère or Gouda adds a smoky depth, while Monterey Jack gives a milder flavor. For a sharper taste, use extra sharp cheddar. The Parmesan is essential for umami, but you can substitute with Pecorino Romano for a saltier kick.
  • If you prefer a thicker sauce, mix 1 teaspoon of xanthan gum with the heavy cream before adding it to the skillet. This is a common low-carb thickener that won't add carbs. Alternatively, let the sauce simmer for an extra 2-3 minutes to reduce and concentrate flavors.
  • This casserole is naturally low carb and keto-friendly. Each serving contains about 6g net carbs (total carbs minus fiber). To keep it truly low carb, ensure your chicken broth is unsweetened and check labels on cream cheese for hidden sugars.
  • For meal prep, assemble the casserole completely but do not bake. Cover and refrigerate for up to 24 hours. When ready to bake, add 5-10 minutes to the baking time since the dish starts cold. You can also freeze the unbaked casserole for up to 3 months; thaw overnight in the fridge before baking.

Variations

  • Vegetarian Version: Replace chicken with 1.5 lbs of firm tofu (pressed and cubed) or a mix of mushrooms (cremini, shiitake, and oyster) for a hearty vegetarian alternative. Sauté the tofu or mushrooms until golden brown before adding the sauce. The creamy sauce and cheese provide plenty of protein and flavor. You can also add cauliflower florets for extra bulk.
  • Spicy Southwest Twist: Add 1 diced jalapeño (seeds removed for less heat) along with the garlic, and substitute the cheddar with pepper jack cheese. Stir in 1/2 teaspoon of cumin and 1/2 teaspoon of chili powder into the sauce. Top with sliced avocado and a dollop of sour cream before serving. This variation brings a smoky, spicy kick.
  • Bacon and Mushroom Upgrade: Cook 4 slices of bacon until crispy, then crumble. Sauté 8 oz sliced mushrooms in the bacon fat until golden. Add the mushrooms and bacon to the casserole along with the chicken. The bacon adds a salty crunch, while mushrooms bring an earthy umami depth that pairs beautifully with the creamy sauce.
  • Dairy-Free Adaptation: Use full-fat canned coconut milk instead of heavy cream, and dairy-free cream cheese alternative. Replace the shredded cheeses with a dairy-free melting shreds (look for those based on coconut or cashew). Nutritional yeast can be added for a cheesy flavor. The texture will be slightly different but still creamy and delicious.
  • Add More Veggies: Boost the vegetable content by adding 1 cup of chopped cauliflower, 1/2 cup of diced bell peppers, or a handful of spinach stirred in just before baking. These vegetables add color, fiber, and nutrients without significantly increasing carbs. Just ensure any watery vegetables (like zucchini) are sautéed first to remove excess moisture.

Nutrition

  • Calories410 kcal
  • Total Fat28g
  • Saturated Fat15g
  • Cholesterol145mg
  • Sodium680mg
  • Total Carbohydrates8g
  • Dietary Fiber2g
  • Sugars3g
  • Protein34g

Common Questions

Can I use frozen chicken breasts?
Yes, but you must thaw them completely before cooking. Frozen chicken will release excess water and steam instead of searing, leading to a less flavorful and potentially watery casserole. For best results, thaw in the refrigerator overnight. If you’re short on time, you can poach the chicken directly in the sauce, but you’ll miss the browning flavor.
How do I store leftovers and how long do they last?
Store leftovers in an airtight container in the refrigerator for up to 4 days. The flavors meld and deepen overnight, making it even tastier the next day. To reheat, microwave individual portions for 1-2 minutes or warm in a 350°F oven for about 10 minutes. You can also freeze the casserole for up to 3 months. Thaw overnight in the fridge and reheat as directed.
Can I make this casserole ahead of time?
Absolutely! Assemble the casserole completely (without baking), cover tightly with foil or plastic wrap, and refrigerate for up to 24 hours. When ready to bake, remove from the fridge while the oven preheats, then bake as directed, adding 5-10 minutes to the baking time. You can also freeze it unbaked for up to 3 months; thaw overnight in the refrigerator before baking.
Is this recipe gluten-free?
Yes, this recipe is naturally gluten-free as it contains no wheat, flour, or pasta. However, always check the labels on your chicken broth and cream cheese to ensure they are certified gluten-free, as some brands may contain additives with gluten. The dish is also low carb and keto-friendly.
Can I substitute the heavy cream with something lighter?
For a lower-fat option, you can use half-and-half or whole milk, but the sauce will be thinner and less rich. To maintain creaminess without heavy cream, you can use a mixture of 1/4 cup cream cheese and 1/4 cup milk, or try unsweetened almond milk thickened with a little xanthan gum. Keep in mind that the calorie and fat content will decrease, but so will the indulgent texture.
My casserole turned out watery. What went wrong?
Watery casserole is usually due to excess moisture from broccoli or not draining the chicken properly. If using frozen broccoli, thaw and pat dry thoroughly. Avoid overcooking the sauce before baking; it should be thick enough to coat the back of a spoon. Also, ensure your chicken is patted dry before searing. If the casserole is still watery after baking, you can place it back in the oven uncovered for 5-10 minutes to evaporate some liquid.
Can I add rice or pasta to make it more filling?
This recipe is designed to be low carb and noodle-free, but you can certainly add cooked cauliflower rice or shirataki noodles (rinsed and drained) for a low-carb option. If you’re not concerned about carbs, stir in 2 cups of cooked rice or small pasta shapes like elbow macaroni before baking. Adjust seasoning accordingly, as the added starch may dilute the flavor.