When dinnertime rolls around, I always reach for recipes that deliver comfort without the fuss. This Keto Chicken Broccoli Casserole has become my go-to weeknight savior. It’s creamy, cheesy, and incredibly satisfying.
The combination of tender chicken and vibrant broccoli swimming in a garlicky cream sauce is pure magic. Every bite delivers that rich, indulgent flavor you crave on a keto diet. And the best part? It’s ready in just 25 minutes.
I love one-pan meals, especially on busy weeknights. Less cleanup means more time relaxing after dinner. This casserole lets me cook everything in a single oven-safe skillet. No juggling multiple pots or coordinating side dishes.
This recipe strikes the perfect balance between indulgence and nutrition. With 32 grams of protein per serving, it keeps you full and energized. Plus, at only 6.8 net carbs, it fits beautifully into any keto meal plan.
Why You’ll Love This Keto Casserole
Quick and effortless: Using pre-cooked chicken cuts your prep time dramatically. You’ll have dinner on the table faster than ordering takeout.
Restaurant-quality flavor: The homemade Alfredo sauce tastes like something from an upscale Italian restaurant. The garlic and Parmesan create depth that store-bought sauces can’t match.
Perfect for meal prep: Make this casserole ahead and reheat throughout the week. It actually tastes even better the next day as flavors meld together.
Kid-approved comfort food: Even picky eaters love this cheesy, creamy dish. It’s become a regular request in my household.
High protein, low carb: Each serving packs a serious protein punch while keeping carbs minimal. It’s ideal for anyone following a keto or low-carb lifestyle.
Versatile and customizable: Swap the mozzarella for cheddar or add your favorite seasonings. This recipe adapts easily to your preferences.
What Makes This Recipe Special
I’ve made countless chicken casseroles over the years. This version stands out because it doesn’t rely on heavy cream cheese or condensed soup. The sauce gets its thickness naturally from reducing the heavy cream.
The broccoli stays perfectly tender-crisp, not mushy or overcooked. I use a full pound of broccoli because I believe vegetables should be the star alongside the protein. Why skimp on the good stuff?
The two-cheese combination creates incredible texture. Mozzarella provides that stretchy, gooey quality we all love. Parmesan adds a sharp, nutty flavor that elevates the entire dish.
Prep Time: 10 minutes | Cook Time: 15 minutes | Total Time: 25 minutes
Servings: 4 | Difficulty: Easy
Ingredients & Instructions
Ingredient Notes
Cooked chicken: I typically use rotisserie chicken from the grocery store. It’s convenient and already seasoned. Leftover grilled chicken or baked chicken breasts work equally well. Just chop it into bite-sized pieces.
Broccoli florets: Fresh broccoli gives the best texture and flavor. Choose firm, bright green florets without yellow spots. Frozen broccoli can substitute in a pinch (see tips below).
Heavy whipping cream: This is essential for a thick, luxurious sauce. Don’t substitute with half-and-half or milk. The high fat content creates the creamy consistency without any thickeners.
Mozzarella cheese: I prefer shredding my own from a block. Pre-shredded cheese contains anti-caking agents that prevent smooth melting. Fresh mozzarella creates that perfect gooey texture.
Parmesan cheese: Freshly grated Parmesan makes a noticeable difference. The pre-grated stuff in the green can works, but fresh tastes infinitely better. It adds a sophisticated depth to the sauce.
Butter: I use unsalted butter to control the sodium level. Salted butter works too, just reduce the added salt accordingly.
Garlic: Fresh minced garlic is non-negotiable here. Jarred garlic doesn’t have the same aromatic punch. Four cloves provide robust flavor without overwhelming the dish.
Ingredients Table
| Ingredient | Quantity | Notes |
|---|---|---|
| Butter | 2 tbsp (28.4 g), divided | Unsalted preferred |
| Broccoli florets | 16 oz (453.59 g), chopped | Fresh, coarsely chopped |
| Garlic | 4 cloves | Minced fresh |
| Heavy whipping cream | 3/4 cup (177.44 ml) | Full-fat only |
| Mozzarella cheese | 1 1/3 cups (149.33 g), divided | Freshly shredded |
| Parmesan cheese | 1/3 cup (33.33 g) | Freshly grated |
| Salt and pepper | To taste | Season generously |
| Cooked chicken | 1 1/2 lb (680.39 g) | About 4 cups chopped |
Step-by-Step Instructions
Step 1: Prepare the broccoli
Melt 1 tablespoon of butter in a large oven-safe skillet over medium-high heat. Add the chopped broccoli florets to the pan. Sauté for 4-5 minutes, stirring occasionally.
The broccoli should turn bright green and become just tender. You want a slight crunch remaining. Don’t overcook at this stage since it’ll continue cooking in the oven.
Transfer the sautéed broccoli to a bowl and set aside. Keep it nearby for later.
Step 2: Create the garlic cream sauce
Add the remaining tablespoon of butter to the same skillet. Let it melt completely over medium heat.
Add the minced garlic to the melted butter. Sauté for about 30-45 seconds until fragrant. Be careful not to burn the garlic. It should smell amazing but not turn brown.
Pour in the heavy whipping cream. Increase the heat slightly and bring to a gentle simmer. Let the cream reduce by about half, which takes 3-4 minutes. Stir occasionally to prevent scorching.
Step 3: Incorporate the cheeses
Lower the heat to medium-low. Add 1 cup of the shredded mozzarella and all the Parmesan cheese.
Stir continuously until the cheeses melt completely into the cream. The sauce should become thick and glossy. This takes about 2 minutes.
Season with salt and pepper to taste. I usually add about 1/2 teaspoon of salt and 1/4 teaspoon of pepper. Adjust based on your preference.
Step 4: Combine everything
Add the cooked chicken and sautéed broccoli back into the skillet. Stir everything together until the chicken and broccoli are evenly coated with the creamy cheese sauce.
Spread the mixture evenly in the pan. Sprinkle the remaining 1/3 cup of mozzarella cheese over the top. Make sure to cover the entire surface.
Step 5: Broil to perfection
Turn your oven’s broiler to high. Position the oven rack about 6 inches from the heating element.
Place the skillet under the broiler. Watch it carefully! The cheese should melt and turn golden brown in 2-3 minutes.
Remove the skillet when the cheese is bubbly and has golden-brown spots. Let it cool for 2-3 minutes before serving. The casserole will be extremely hot straight from the oven.
Tips, Variations & FAQs
Pro Tips for Success
Choose the right skillet: An oven-safe skillet is essential for this recipe. Cast iron works beautifully, but any heavy-bottomed pan that can handle broiler heat works fine. Check your pan’s handle to ensure it’s oven-safe.
Don’t skimp on broccoli: Many casserole recipes use barely a cup of vegetables. I pack in 16 ounces because it makes this a complete, balanced meal. The extra broccoli adds fiber and nutrients without extra carbs.
Watch the broiler closely: Broilers vary significantly in intensity. Stay near the oven during this final step. The line between perfectly golden and burnt happens in seconds.
Use rotisserie chicken for flavor: Store-bought rotisserie chicken isn’t just convenient. It’s already seasoned and incredibly moist. This adds extra flavor to the casserole without any extra effort.
Let the cream reduce properly: Don’t rush the simmering step. Reducing the cream by half concentrates the flavor and creates a naturally thick sauce. This takes about 3-4 minutes of patient stirring.
Using Frozen Broccoli
Frozen broccoli can work in this recipe with some adjustments. Thaw it completely first and squeeze out excess moisture. Frozen broccoli releases water when heated, which can make your sauce watery.
Skip the sautéing step entirely with frozen broccoli. Start directly with making the cream sauce. Add the thawed, drained broccoli when you combine everything in step 4.
I still prefer fresh broccoli for better texture. Frozen tends to get mushy more easily. But on busy nights, frozen is absolutely acceptable.
Storage and Reheating
Store leftovers in an airtight container in the refrigerator. They’ll keep well for 3-4 days. The flavors actually deepen overnight, making leftovers particularly delicious.
Reheat individual portions in the microwave for 1-2 minutes. Add a splash of cream if the sauce seems too thick. You can also reheat the entire casserole covered in a 350°F oven for 15-20 minutes.
This casserole freezes reasonably well for up to 2 months. The texture changes slightly upon thawing, but it’s still tasty. Thaw overnight in the refrigerator before reheating.
Delicious Variations
Different cheeses: Swap mozzarella for sharp cheddar, Gruyere, or Fontina. Each cheese brings a unique flavor profile. Mix multiple cheeses for extra complexity.
Add bacon: Crumbled bacon on top before broiling adds smoky richness. It pairs beautifully with the creamy sauce.
Spice it up: Add red pepper flakes or a dash of cayenne for heat. A teaspoon of Dijon mustard in the sauce adds tangy depth.
Extra vegetables: Cauliflower florets work wonderfully alongside or instead of broccoli. Sliced mushrooms add an earthy note.
Herb boost: Fresh thyme, basil, or Italian seasoning elevate the flavor. Stir herbs into the sauce or sprinkle on top before serving.
Nutritional Information (Per Serving)
- Calories: 485
- Protein: 32g
- Total Carbs: 6.8g
- Fiber: 2.3g
- Net Carbs: 4.5g
- Fat: 37g
Frequently Asked Questions
Can I make this casserole ahead of time?
Absolutely! Prepare the casserole through step 4, but don’t broil yet. Cover tightly and refrigerate for up to 24 hours. When ready to serve, let it sit at room temperature for 15 minutes, then broil as directed. You may need an extra minute under the broiler since it starts cold.
What can I substitute for heavy cream?
For keto dieters, heavy cream is ideal. If you’re not strictly low-carb, half-and-half can work but won’t be as thick. Add a tablespoon of cream cheese to help thicken the sauce. Avoid regular milk as it won’t create the proper consistency.
How do I prevent the broccoli from getting mushy?
Keep the initial sauté brief, just 4-5 minutes. The broccoli should still have a slight crunch. It continues cooking under the broiler, so undercooking initially is better than overdoing it. Fresh broccoli holds up better than frozen.
Can I use a different protein?
Turkey works beautifully in place of chicken. Cooked shrimp makes a delicious variation (reduce broiling time to 1-2 minutes). For vegetarians, omit the meat and double the broccoli, adding cauliflower for extra substance.
Why is my sauce too thin?
Make sure you’re using heavy whipping cream, not half-and-half or milk. Let the cream simmer and reduce by half before adding cheese. This concentration is crucial. If your sauce is still thin, simmer it longer until it coats the back of a spoon. The cheese also thickens it significantly.
This Keto Chicken Broccoli Casserole has become a staple in my weekly rotation. It delivers everything I want in a weeknight dinner: speed, flavor, and satisfaction. The creamy garlic sauce makes it feel indulgent, while the high protein content keeps me full for hours.
Whether you’re strictly keto or just looking for a delicious low-carb meal, this casserole delivers. Give it a try tonight and see why it’s earned its place in my regular dinner lineup!
Keto Chicken Broccoli Casserole
Ingredients
- 2 tbsp 28.4 g butter, divided (unsalted preferred)
- 16 oz 453.59 g broccoli florets, coarsely chopped (fresh)
- 4 cloves garlic minced
- 3/4 cup 177.44 ml heavy whipping cream (full-fat only)
- 1 1/3 cups 149.33 g shredded mozzarella cheese, divided (freshly shredded)
- 1/3 cup 33.33 g grated Parmesan cheese (freshly grated)
- Salt and pepper to taste
- 1 1/2 lb 680.39 g cooked chicken, chopped (about 4 cups)
Instructions
- Prepare the broccoli:
- Melt 1 tablespoon of butter in a large oven-safe skillet over medium-high heat.
- Add the chopped broccoli florets and sauté for 4-5 minutes, stirring occasionally, until bright green and just tender.
- Transfer the sautéed broccoli to a bowl and set aside.
- Create the garlic cream sauce:
- Add the remaining tablespoon of butter to the same skillet and let it melt completely over medium heat.
- Add the minced garlic and sauté for 30-45 seconds until fragrant (don’t let it brown).
- Pour in the heavy whipping cream, increase heat slightly, and bring to a gentle simmer.
- Let the cream reduce by about half, stirring occasionally, for 3-4 minutes.
- Incorporate the cheeses:
- Lower the heat to medium-low.
- Add 1 cup of the shredded mozzarella and all the Parmesan cheese.
- Stir continuously until the cheeses melt completely into the cream (about 2 minutes).
- Season with salt and pepper to taste (about 1/2 teaspoon salt and 1/4 teaspoon pepper).
- Combine everything:
- Add the cooked chicken and sautéed broccoli back into the skillet.
- Stir everything together until evenly coated with the creamy cheese sauce.
- Spread the mixture evenly in the pan.
- Sprinkle the remaining 1/3 cup of mozzarella cheese over the top, covering the entire surface.
- Broil to perfection:
- Turn your oven’s broiler to high and position the oven rack about 6 inches from the heating element.
- Place the skillet under the broiler and watch carefully.
- Broil for 2-3 minutes until the cheese is bubbly with golden-brown spots.
- Remove from oven and let cool for 2-3 minutes before serving.
Notes
Using frozen broccoli: Thaw completely and squeeze out excess moisture. Skip the sautéing step and add the drained broccoli directly in step 4.
Storage: Store leftovers in an airtight container in the refrigerator for 3-4 days. Reheat in microwave for 1-2 minutes or in a 350°F oven for 15-20 minutes covered.
