Keto chicken broccoli casserole — the cheesy low carb dinner the whole family will ask for again

There is something about a casserole that just feels like home. It is not the most exciting word in the culinary world — I will give you that. But pull one of these out of the oven, golden and bubbling, filling your kitchen with the smell of melted cheese and savory chicken, and nobody is complaining about the name.

I started making this keto chicken broccoli casserole on nights when I needed something reliable. Something that would feed everyone, require minimal active effort, and taste like I actually tried.

It checks every single one of those boxes. The creamy sauce pulls everything together, the broccoli stays vibrant and tender, and the cheese topping does exactly what a cheese topping should do — it gets golden, it gets bubbly, and it makes everything underneath it better.

The best part? This comes together in under an hour, uses ingredients you can find at any grocery store, and reheats beautifully for lunch the next day. If you have been looking for a low carb dinner that the whole family will actually eat without a single complaint — this is it. :)

Why you'll love this recipe

• That cheese topping — A combination of sharp cheddar and mozzarella melts into a golden, bubbly crust that makes this casserole look and taste like something you ordered at a restaurant. It is the crown jewel of the whole dish.
• Rich creamy sauce with no flour — The sauce gets its thickness from cream cheese and heavy cream, which means it is naturally gluten free and keto friendly without sacrificing any of the richness you expect from a good casserole.
• One baking dish, minimal cleanup — Everything comes together in a single casserole dish. Less mess, less time cleaning up, more time enjoying dinner.
• Family approved — This is the kind of low carb dinner that non-keto family members eat without even realizing it is a health-conscious meal. That is the highest possible praise a recipe can get.
• Great for meal prep and freezing — Make it ahead, portion it out, freeze it for later. This casserole is one of the most practical recipes in the keto dinner lineup.
• Under an hour start to finish — With just 15 minutes of active prep and 40 minutes in the oven, dinner is on the table in under an hour with most of that time completely hands-off.

Ingredients with key notes

For the casserole base:

• 1.5 lbs boneless skinless chicken breasts, cut into bite-sized chunks — You want even, bite-sized pieces so they cook uniformly and distribute well throughout the casserole. You can also use rotisserie chicken to save time — just shred it and skip the cooking step.
• 4 cups fresh broccoli florets — Cut them into medium-sized florets, not too small or they will disintegrate during baking. Fresh broccoli is strongly preferred over frozen here — frozen releases too much water during baking and can make the casserole watery.
• 1 tbsp olive oil — For cooking the chicken.
• 1 tsp garlic powder
• 1 tsp onion powder
• 1/2 tsp smoked paprika
• Salt and black pepper to taste

For the creamy sauce:

• 4 oz full fat cream cheese, softened — This is the base of your sauce and what gives it that thick, rich, velvety texture without any flour or starch. Make sure it is properly softened before you start or it will be lumpy.
• 1/2 cup heavy cream — Adds richness and helps bring the sauce to the right consistency.
• 1/2 cup chicken broth — Low sodium. Loosens the sauce slightly and adds a savory depth that balances the richness of the cream cheese.
• 3 garlic cloves, minced — Fresh garlic makes a real difference in this sauce. Do not skip it.
• 1 tsp Dijon mustard — Adds a subtle tang that cuts through the richness of the sauce and gives it a more complex flavor. You won't taste the mustard specifically — it just makes everything taste more interesting.
• 1/2 tsp dried thyme
• 1/2 tsp dried parsley
• Salt and pepper to taste

For the cheese topping:

• 1 cup shredded sharp cheddar cheese — Sharp cheddar delivers the most flavor impact. Pre-shredded works but freshly shredded melts more smoothly because it doesn't have the anti-caking powder that bagged cheese contains.
• 1/2 cup shredded mozzarella cheese — Adds that satisfying cheese pull and helps the topping melt into an even, gooey layer. The combination of cheddar and mozzarella is the move here — cheddar for flavor, mozzarella for melt.

Step-by-step instructions

Step 1: Preheat the oven and prep the dish

Preheat your oven to 375°F (190°C). Lightly grease a 9x13 inch baking dish with cooking spray or a small amount of butter. Set aside. Getting this done first means your dish is ready to go the moment your filling is assembled.

Step 2: Cook the chicken

Season the chicken chunks with garlic powder, onion powder, smoked paprika, salt, and black pepper. Heat olive oil in a large skillet over medium-high heat. Add the chicken in a single layer — work in batches if needed — and cook for 4-5 minutes per side until golden on the outside and just cooked through. The chicken will finish cooking in the oven, so don't stress about getting it perfectly done at this stage. Transfer to a plate and set aside.

Step 3: Steam the broccoli

While the chicken cooks, steam the broccoli florets until just barely tender — about 3-4 minutes. You want them bright green and slightly underdone at this stage because they will continue cooking in the oven. Overcooked broccoli going into a casserole means mushy broccoli coming out, and nobody wants that. Drain well and pat dry with paper towels to remove as much moisture as possible.

Step 4: Make the creamy sauce

In the same skillet you cooked the chicken — don't clean it — reduce the heat to medium. Add the minced garlic and cook for 60 seconds until fragrant. Add the softened cream cheese and stir it around, letting it melt into the pan. Pour in the heavy cream and chicken broth, whisking constantly to combine everything into a smooth sauce. Add the Dijon mustard, dried thyme, and dried parsley. Season with salt and pepper. Let the sauce simmer for 3-4 minutes, stirring occasionally, until it thickens slightly. Taste and adjust seasoning.

Step 5: Assemble the casserole

Add the cooked chicken and steamed broccoli to the skillet with the sauce and stir gently to coat everything evenly. Transfer the entire mixture to your prepared baking dish and spread it out into an even layer. Make sure the broccoli and chicken are well distributed throughout rather than all the broccoli ending up on one side — which it will try to do. :)

Step 6: Add the cheese topping and bake

Mix the shredded cheddar and mozzarella together in a bowl, then sprinkle the combined cheese evenly over the entire surface of the casserole. Don't hold back — an even, generous layer of cheese is what gives you that beautiful golden crust.

Slide the dish into the preheated oven and bake for 25-30 minutes, until the cheese is fully melted, golden brown in spots, and the sauce is bubbling around the edges. If you want the cheese topping a little more browned and crispy, switch to broil for the last 2-3 minutes and keep a close eye on it.

Step 7: Rest and serve

Pull the casserole out of the oven and let it rest for 5 minutes before serving. This allows the sauce to settle and makes it easier to scoop clean portions. Garnish with a pinch of dried parsley or fresh herbs if you like, and serve hot.

Serving suggestions

• As a complete standalone dinner — This casserole has protein, vegetables, and a rich sauce all in one dish. It genuinely does not need anything else, though a simple side salad never hurts.
• Over cauliflower rice — Spoon a generous portion of the casserole over a bed of cauliflower rice for a more substantial meal that soaks up all that creamy sauce.
• With a simple green salad — A crisp salad with a light vinaigrette provides a fresh, acidic contrast to the richness of the casserole and rounds out the meal nicely.
• With roasted asparagus or green beans — Both vegetables complement the flavors of this casserole without overpowering it. Roast them simply with olive oil, salt, and pepper.
• As a meal prep lunch — Portion the casserole into individual containers and pair with a small side salad for a complete, satisfying lunch that reheats beautifully.

Storage tips

Refrigerator: Let the casserole cool completely before covering the baking dish tightly with plastic wrap or transferring portions to airtight containers. Store in the fridge for up to 4 days. The sauce thickens significantly as it cools — this is completely normal and it loosens right back up when reheated.

Freezer: This casserole freezes exceptionally well, making it one of the best keto freezer meals you can have on hand. Let it cool completely, then either freeze the whole casserole covered tightly in plastic wrap and foil, or portion it into individual freezer-safe containers. Freeze for up to 3 months. For best results, freeze before adding the cheese topping and add fresh cheese when you are ready to bake from frozen.

Reheating: Reheat individual portions in the microwave in 90-second intervals, stirring between each, until warmed through. For the whole casserole, cover with foil and reheat in a 350°F oven for 20-25 minutes until hot throughout. Remove the foil for the last 5 minutes to re-melt and re-crisp the cheese topping. Add a small splash of chicken broth before reheating if the sauce looks too thick.

A quick word before you go

Comfort food has a reputation for being indulgent and off limits when you are trying to eat well. This casserole disagrees with that reputation entirely. It is rich, creamy, cheesy, and deeply satisfying — and it happens to be low carb, high protein, and genuinely nourishing at the same time.

That is the whole point of everything I make here at Recipes By Kip. Food that takes care of you without making you feel like you are missing out. Food that the people you love will eat happily, whether they care about macros or not.

Make this one on a weeknight when you need something reliable and delicious. Pull it out of the oven golden and bubbling. Watch it disappear from the baking dish faster than you expected.

That is a good dinner. That is what this is all about.

With gratitude, Kip.