Broccoli Chicken Casserole is one of those classic comfort dishes that brings together tender chicken, crisp broccoli, and a creamy, cheesy sauce all baked until bubbly and golden on top. It’s a warm, hearty meal that’s both satisfying and simple, perfect for busy weeknights or family dinners.
I always love making this casserole when I want something cozy but don’t want to spend hours in the kitchen. It’s easy to throw together with just a few ingredients, and the mix of textures—from the soft chicken to the slightly crunchy broccoli—makes every bite enjoyable. Plus, the creamy sauce hides a bit of secret goodness, like a hint of garlic or a sprinkle of your favorite cheese.
My favorite way to serve this casserole is straight from the oven with a side of crusty bread or a fresh green salad—it balances out the richness just right. I find it’s a dish that people of all ages go back for seconds on, and it even makes great leftovers for lunch the next day. Whenever I’m craving something warm and filling that feels like a hug on a plate, this Broccoli Chicken Casserole is exactly what I make.
Key Ingredients & Substitutions
Chicken: Cooked chicken breast works best here. I like using leftover roasted chicken or even rotisserie chicken for easy prep. You can also swap for cooked turkey or tofu for a vegetarian twist.
Broccoli: Fresh broccoli keeps a nice texture after baking. If you only have frozen, thaw and drain it well to avoid a soggy casserole.
Cheese: Cheddar adds great flavor and meltiness. Feel free to mix in mozzarella or Monterey Jack for a milder taste. Parmesan on top gives a nice sharp finish.
Milk & Flour (for sauce): Whole milk makes the sauce creamy. You can use 2% or a plant-based milk (like oat or almond) but keep the flour to help thicken.
Panko Breadcrumbs: These are optional but add a lovely crunch. You can replace with crushed crackers, cornflakes, or skip them entirely for a softer top.
How Do I Make a Smooth, Thick Cheese Sauce Without Lumps?
The cheese sauce is key for a creamy casserole. Here’s how to get it just right:
- Melt butter on medium heat and add garlic for flavor.
- Whisk in flour and cook 1-2 minutes to form a roux, stirring to avoid lumps.
- Slowly pour in milk while whisking constantly to keep it smooth.
- Keep stirring until the sauce thickens and coats the back of a spoon (about 4-5 minutes).
- Remove from heat and stir in cheeses until melted fully.
- Season with salt, pepper, and thyme for balanced flavor.
Taking your time with each step helps avoid lumps. If the sauce feels too thick, stir in a splash more milk. The result is a creamy base that holds the casserole together beautifully.
Equipment You’ll Need
- 9×13-inch baking dish – I use this size because it’s just right for even baking and easy to serve.
- Large pot – for cooking pasta; I like a big one to prevent sticking and make it easier to stir.
- Medium saucepan – to make the cheese sauce; it’s perfect for whisking without spilling.
- Whisk – keeps the sauce smooth and lump-free, making sure everything blends well.
- Steamer basket or microwave-safe dish – to steam or blanch the broccoli quickly.
- Measuring cups and spoons – for accurate ingredient amounts, so my casserole turns out just right.
- Mixing bowls – for combining ingredients before baking, helping everything get evenly coated.
- Optional: Panko breadcrumb shaker or small bowl – if you want a crunchy topping, I use this to evenly sprinkle breadcrumbs over the dish.
Flavor Variations & Add-Ins
- Swap out cheddar for mozzarella or Monterey Jack for a milder, melty cheese flavor.
- Add cooked bacon bits or ham for extra savory richness that everyone loves.
- Mix in sliced mushrooms, cooked carrots, or sun-dried tomatoes to boost the veggie flavors.
- Sprinkle red pepper flakes or add a dash of hot sauce if you like a little heat in your casserole.
Broccoli Chicken Casserole
Ingredients You’ll Need:
- 2 cups cooked chicken breast, diced or shredded
- 3 cups fresh broccoli florets
- 2 cups cooked pasta (such as small shells or macaroni)
- 2 cups shredded cheddar cheese (or a mild cheese blend)
- 1 cup grated Parmesan cheese
- 3 tablespoons butter
- 3 tablespoons all-purpose flour
- 2 cups milk (whole or 2%)
- 2 cloves garlic, minced
- 1 teaspoon dried thyme (plus fresh thyme for garnish if desired)
- 1 teaspoon salt
- ½ teaspoon black pepper
- ½ cup panko breadcrumbs (optional, for crunchy topping)
- 1-2 tablespoons olive oil or melted butter (to toss with breadcrumbs)
How Much Time Will You Need?
This casserole takes about 20 minutes to prep, including cooking pasta and steaming broccoli, plus 20-25 minutes baking time. So, roughly 45 minutes from start to finish for a delicious home-cooked meal.
Step-by-Step Instructions:
1. Preheat and Prepare
Preheat your oven to 375°F (190°C). Lightly grease a 9×13 inch baking dish to keep the casserole from sticking.
2. Cook Pasta and Broccoli
Cook the pasta according to package instructions until al dente. Drain it well and set aside. Steam or blanch the broccoli just until tender but still crisp. Drain and set aside.
3. Make the Cheese Sauce
In a medium saucepan, melt the butter over medium heat. Add the minced garlic and cook for 1 minute until fragrant. Whisk in the flour, cooking 1-2 minutes to form a smooth paste (roux). Gradually whisk in the milk, stirring constantly, until the sauce thickens (about 4-5 minutes). Stir in cheddar and Parmesan cheese until melted and smooth. Season with salt, pepper, and dried thyme.
4. Mix and Assemble
In a large bowl, combine cooked chicken, broccoli, pasta, and the cheese sauce. Stir gently to combine evenly. Transfer this mixture to your prepared baking dish and spread it out evenly.
5. Add Topping and Bake
If using, mix panko breadcrumbs with olive oil or melted butter, then sprinkle evenly over the casserole for a crunchy topping. Bake in your preheated oven for 20-25 minutes, until the casserole is bubbly and the top is golden brown.
6. Serve
Remove from the oven and let cool a few minutes. Garnish with fresh thyme sprigs if you like, then serve warm. This dish pairs nicely with a green salad or some crusty bread.
Enjoy your creamy, cheesy Broccoli Chicken Casserole!
Can I Use Frozen Broccoli Instead of Fresh?
Yes, you can use frozen broccoli, but be sure to thaw and drain it well before adding. This helps prevent excess moisture that can make the casserole soggy.
How Can I Make This Recipe Ahead of Time?
You can assemble the casserole and refrigerate it for up to 24 hours before baking. Just cover it tightly and bake as instructed when ready. Add a few extra minutes to the baking time if baking straight from the fridge.
What’s the Best Way to Store Leftovers?
Store leftovers in an airtight container in the refrigerator for up to 3 days. Reheat gently in the oven or microwave until warmed through, adding a splash of milk if the sauce seems thick.
Can I Substitute the Chicken with Another Protein?
Absolutely! Cooked turkey, ham, or even tofu work well as substitutions, depending on your preference. Just make sure any protein you use is cooked before mixing it into the casserole.