This creamy low carb chicken casserole is packed with tender chicken and broccoli for a healthy keto dinner that satisfies comfort food cravings. Ready in 30 minutes!

Ingredients

Toggle: Metric / US

Instructions

Step 1

Preheat your oven to 375°F (190°C). While the oven heats, prepare your ingredients: cut the chicken breasts into uniform bite-sized pieces (about 1-inch cubes) so they cook evenly. Chop the broccoli into small florets, ensuring they are similar in size for consistent tenderness. Mince the garlic and set aside. Soften the cream cheese by leaving it at room temperature for 15 minutes or microwaving for 10 seconds. This step is crucial because softened cream cheese blends seamlessly into the sauce, preventing lumps and ensuring a velvety smooth texture. The heavy cream should also be at room temperature to avoid curdling when combined with the cream cheese.

Step 1 image
Step 2

Heat 1 tablespoon of olive oil in a large oven-safe skillet over medium-high heat. Once the oil shimmers (about 350°F/175°C), 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 develops deep savory flavor through the Maillard reaction. Remove the chicken with a slotted spoon and set aside on a plate. The chicken will finish cooking in the oven, so slightly undercooking now ensures it stays juicy.

Step 2 image
Step 3

In the same skillet, add the remaining 1 tablespoon of olive oil. Add the broccoli florets and sauté for 2-3 minutes until they turn bright green and are slightly tender but still crisp. You want a slight crunch as the broccoli will continue to cook in the oven. Remove the broccoli and set aside with the chicken. The residual oil and browned bits in the pan will add flavor to the sauce.

Step 3 image
Step 4

Reduce heat to medium. Add the minced garlic to the skillet and cook for 30 seconds until fragrant, stirring constantly to prevent burning. Pour in the heavy cream and add the softened cream cheese. Whisk continuously until the cream cheese has fully melted and the sauce is smooth, about 2-3 minutes. The sauce should be thick enough to coat the back of a spoon. Stir in 1/2 cup of shredded cheddar cheese, Parmesan cheese, onion powder, thyme, salt, pepper, and optional red pepper flakes. Continue whisking until all cheese is melted and the sauce is creamy. Taste and adjust seasoning if needed.

Step 5

Return the cooked chicken and broccoli to the skillet, stirring gently to coat everything evenly with the cheese sauce. Ensure every piece is covered. Sprinkle the remaining 1/2 cup of cheddar cheese evenly over the top. This top layer will melt and create a golden, bubbly crust during baking.

Step 6

Transfer the skillet to the preheated oven and bake for 10-12 minutes, until the casserole is hot and bubbly and the cheese on top is melted and lightly golden. If you prefer a deeper golden crust, switch to broil for the last 2 minutes, watching closely to avoid burning. Remove from oven and let rest for 5 minutes before serving. This resting period 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 directly from the skillet or spoon into serving bowls. This casserole pairs beautifully with a simple side salad or steamed green beans for extra vegetables. Store leftovers in an airtight container in the refrigerator for up to 4 days. Reheat gently in the microwave or on the stovetop with a splash of cream to restore creaminess.

Step 7 image

For best results

  • For the juiciest chicken, consider brining the chicken pieces in a simple saltwater solution (1 tablespoon salt per 2 cups water) for 15-30 minutes before cooking. This enhances moisture retention and seasoning throughout the meat. Alternatively, you can use chicken thighs for even more tenderness and flavor, as they have a higher fat content that stays succulent during baking.
  • To ensure the broccoli doesn't become mushy, blanch it in boiling salted water for 2 minutes, then plunge into ice water before sautéing. This method, called shocking, stops the cooking process and preserves a vibrant green color and crisp-tender texture. If you prefer softer broccoli, skip the ice bath and let it steam in the oven.
  • The cream cheese must be softened to room temperature to avoid lumps. If you're short on time, cut the cream cheese into small cubes and let it sit for 10 minutes, or microwave on low power in 5-second intervals until soft but not melted. Cold cream cheese will seize when added to the hot cream, resulting in a grainy sauce.
  • For a richer flavor, substitute half the heavy cream with full-fat sour cream or crème fraîche. This adds tanginess and a thicker consistency. However, avoid low-fat dairy products as they can curdle or produce a watery sauce due to their lower fat content.
  • If you don't have an oven-safe skillet, transfer the chicken, broccoli, and sauce to a greased 9×13-inch baking dish before topping with cheese and baking. This works perfectly and allows for easy cleanup. Just be sure to scrape all the flavorful browned bits from the skillet into the dish.
  • To make this casserole dairy-free, use full-fat canned coconut milk instead of heavy cream, dairy-free cream cheese, and vegan shredded cheese. The coconut milk will add a subtle sweetness that pairs well with the savory flavors. Nutritional yeast can replace Parmesan for a cheesy flavor without dairy.
  • Meal prep tip: Assemble the casserole completely but do not bake. Cover tightly with foil and refrigerate for up to 24 hours. When ready to bake, add 10-15 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 refrigerator before baking.

Variations

  • Keto Bacon Ranch Version: Add 4 slices of cooked, crumbled bacon and stir in 2 tablespoons of ranch seasoning mix (or homemade blend of dried dill, parsley, chives, garlic powder, onion powder, and salt) to the cream sauce. Top with extra cheddar and bake as directed. The smoky bacon and tangy ranch elevate the flavor profile while keeping carbs negligible.
  • Spicy Buffalo Chicken Casserole: Replace the thyme and onion powder with 1/4 cup of buffalo wing sauce (like Frank's RedHot) and omit red pepper flakes. Add 2 tablespoons of melted butter to the sauce for richness. Serve with blue cheese dressing drizzled on top and celery sticks on the side. This variation adds a kick and is perfect for game day.
  • Mushroom and Spinach Version: Sauté 8 oz sliced mushrooms with the broccoli until golden and moisture evaporates. Stir in 3 cups fresh spinach until wilted before adding the cream sauce. Mushrooms add umami depth and extra fiber, while spinach boosts iron and vitamins. This makes the casserole even more nutrient-dense.
  • Low-Carb Mexican Chicken Casserole: Substitute cheddar with a Mexican cheese blend, add 1 teaspoon cumin and 1 teaspoon chili powder to the sauce. Stir in 1/2 cup diced green chiles and 1/4 cup chopped cilantro. Serve with avocado slices, sour cream, and a sprinkle of cotija cheese. This variation brings vibrant south-of-the-border flavors.
  • Protein-Packed Cottage Cheese Version: For an extra protein boost, replace half the heavy cream with 1/2 cup full-fat cottage cheese (blended until smooth). The cottage cheese adds creaminess and 13g of protein per 1/2 cup without altering the flavor. This is ideal for those on high-protein diets like keto or bodybuilding macros.
  • Cauliflower Rice Casserole: For a heartier dish, stir in 2 cups of riced cauliflower (fresh or frozen, thawed and squeezed dry) along with the chicken and broccoli. The cauliflower mimics noodles or rice, absorbing the creamy sauce while keeping the dish low-carb. Bake an additional 5 minutes to heat through.

Nutrition

  • Calories385 kcal
  • Total Fat28g
  • Saturated Fat15g
  • Cholesterol145mg
  • Sodium620mg
  • Total Carbohydrates8g
  • Dietary Fiber2g
  • Sugars3g
  • Protein32g

Common Questions

Can I use frozen broccoli instead of fresh?
Yes, you can use frozen broccoli florets. However, frozen broccoli contains more water, which can make the casserole watery. To prevent this, thaw the broccoli completely and pat it dry with paper towels before sautéing. You may also need to increase the sauté time to 4-5 minutes to evaporate excess moisture. Alternatively, add the frozen broccoli directly to the sauce and bake for an extra 5 minutes, but expect a slightly softer texture.
How do I store and reheat leftovers?
Store leftovers in an airtight container in the refrigerator for up to 4 days. To reheat, place individual portions in the microwave for 1-2 minutes, stirring halfway. For best results, reheat in a skillet over medium-low heat with a splash of heavy cream or chicken broth to restore the creamy consistency. The casserole can also be frozen for up to 3 months; thaw overnight in the fridge before reheating.
Is this casserole truly keto-friendly?
Yes, this casserole is designed for keto diets with approximately 6g net carbs per serving (based on 4 servings). The main carb sources are broccoli and the small amount of onion powder. Heavy cream, cream cheese, and cheeses are low in carbs. To reduce carbs further, replace broccoli with more chicken or add spinach, zucchini, or cauliflower. Always check labels on cheese and cream for hidden carbs.
Can I substitute the heavy cream with something lighter?
Substituting heavy cream with half-and-half or milk will result in a thinner sauce and lower fat content, which may affect the keto macros. For a lighter option, use half heavy cream and half chicken broth, and add a teaspoon of xanthan gum or glucomannan powder to thicken. However, the sauce will be less rich. Full-fat coconut milk is a good dairy-free alternative that maintains creaminess.
Why did my sauce turn out grainy?
A grainy sauce usually results from cold cream cheese or overheating. Ensure cream cheese is softened to room temperature before adding. Also, avoid boiling the sauce; keep it at a gentle simmer. If the sauce separates, remove from heat and whisk in a tablespoon of cold heavy cream or a splash of lemon juice to help emulsify. Using fresh, high-quality cream cheese (full-fat block) also prevents graininess.
Can I add other vegetables?
Absolutely! This casserole is versatile. Add sliced bell peppers, zucchini, mushrooms, or spinach. For low-carb options, stick to non-starchy vegetables. If adding watery vegetables like zucchini, sauté them first to remove excess moisture, or roast them to concentrate flavor. Avoid starchy vegetables like potatoes or corn to keep the dish low-carb.
How do I make this casserole gluten-free?
This recipe is naturally gluten-free as it contains no flour, pasta, or breadcrumbs. However, always check labels on spices and cheese for potential cross-contamination. If you use pre-shredded cheese, some brands add anti-caking agents that may contain gluten, so shred your own from a block to be safe. The recipe is celiac-friendly as written.
What can I use instead of cream cheese?
For a similar creamy texture, you can use mascarpone cheese, full-fat ricotta (blended smooth), or a dairy-free cream cheese alternative. Mascarpone will yield a richer sauce, while ricotta adds a slightly grainy texture but still works. If using Neufchâtel (lower fat cream cheese), note that it has less fat and may not thicken as well.