Name: Broccoli Chicken Casserole Recipe
Prep time: 15 min
Cook time: 45 min
Total time: 1 h
Cuisine: American
Ingredients: 8 ounces uncooked pasta; 1 large head of broccoli, cut into bite-sized florets (about 1 pound); 2 tablespoons butter or olive oil; 1 small white onion, thinly sliced; 8 ounces baby bella (cremini) mushrooms, thinly sliced; 4 cloves garlic, minced; 3 tablespoons flour; 1 cup chicken or vegetable stock; 1 1/2 cups milk; 1 teaspoon Dijon mustard; 1/2 teaspoon fine sea salt; 1/4 teaspoon freshly-cracked black pepper; 2 cups (8 ounces) shredded sharp cheddar cheese, divided; 2 cups diced or shredded cooked chicken

Print Recipe· 4.2 from 32 reviews

There’s something incredibly comforting about a good casserole, and this Broccoli Chicken Casserole Recipe hits all the right notes with its hearty, cheesy goodness and wholesome veggies. Imagine tender pasta and vibrant broccoli mingling with tender chicken pieces and a luscious, creamy mushroom sauce, all topped with a golden blanket of melted sharp cheddar. It’s the kind of dish that makes you feel cozy inside and keeps everyone coming back for seconds without a single word needed. Perfect for a family dinner or when you want to impress friends with minimal fuss, this recipe brings warmth, flavor, and that undeniable home-cooked charm right to your table.

Ingredients You’ll Need

A white rectangular baking dish filled with a creamy pasta bake showing three clear layers: the bottom layer is light yellow twisted pasta mixed with green broccoli florets, the middle layer has medium brown sautéed mushroom slices, and the top layer has golden brown grilled chicken pieces along with melted white cheese sprinkled with black pepper and small bits of fresh green herbs. A woman's hand is holding a wooden spoon scooping some of the pasta bake from the corner, with the white marbled surface underneath. The dish looks warm and rich with a mix of creamy and textured ingredients photo taken with an iphone --ar 4:5 --v 7

Getting great results starts with great ingredients, and this Broccoli Chicken Casserole Recipe is no exception. Each element adds its own special flair—whether it’s the sharpness of the cheddar, the earthiness of the mushrooms, or the fresh crunch of broccoli—making every bite a delight.

8 ounces uncooked pasta: Provides the comforting, hearty base for the casserole.
1 large head of broccoli, cut into bite-sized florets: Adds vibrant color and essential nutrition to the dish.
2 tablespoons butter or olive oil: Perfect for sautéing the veggies and bringing out their flavor.
1 small white onion, thinly sliced: Adds sweetness and depth when sautéed.
8 ounces baby bella (cremini) mushrooms, thinly sliced: Offers an earthy richness and meaty texture.
4 cloves garlic, minced: Packs a punch of fragrant, savory goodness.
3 tablespoons flour: Essential for thickening the luscious sauce.
1 cup chicken or vegetable stock: Builds a flavorful foundation for the creamy sauce.
1 1/2 cups milk: Gives the sauce its creamy, dreamy texture.
1 teaspoon Dijon mustard: Adds a subtle tang that elevates the sauce’s depth.
1/2 teaspoon fine sea salt: Enhances all the vibrant flavors.
1/4 teaspoon freshly-cracked black pepper: Adds a gentle heat and complexity.
2 cups (8 ounces) shredded sharp cheddar cheese, divided: Melts beautifully and brings that classic cheesy comfort.
2 cups diced or shredded cooked chicken: Makes the casserole truly satisfying and protein-packed.

How to Make Broccoli Chicken Casserole Recipe

Step 1: Prepare the Oven and Pasta

Start by preheating your oven to 400°F to ensure it’s ready when your casserole is assembled. Next, cook the pasta in a large pot of generously salted boiling water until just al dente. This ensures a little bite so it won’t get mushy after baking. About one minute before the pasta finishes cooking, toss in the broccoli florets right into the pot so they steam and cook gently alongside the pasta. Once done, drain both pasta and broccoli together and set them aside—this combo forms the heart of your casserole.

Step 2: Sauté Onions, Mushrooms, and Garlic

While the pasta and broccoli cook, heat butter or olive oil in a large sauté pan over medium-high heat. Add thinly sliced onions and gently cook for about three minutes, letting them soften and develop a mild sweetness. Then add the mushrooms and minced garlic, cooking for another five minutes or so until the mushrooms release their moisture and become tender. This aromatic mix will build amazing flavor for your sauce and the whole casserole.

Step 3: Make the Creamy Sauce

Sprinkle the flour evenly over the cooked veggies and stir it in well to create a roux that will thicken your sauce beautifully. Cook for one minute to take away any raw flour taste, then slowly whisk in the chicken or vegetable stock, stirring constantly to break up clumps. Once that’s smooth, add the milk, Dijon mustard, salt, and black pepper. Keep stirring as you bring the sauce to a gentle simmer—this is where it thickens and becomes silky. Remove from heat and stir in half of the shredded cheddar until melted and perfectly blended. Taste and adjust seasoning if you need to.

Step 4: Assemble the Casserole

Grab a large 9 x 13-inch baking dish and combine the cooked pasta, broccoli, mushroom sauce, and chicken. Toss everything together so every bite has all the flavors mingling. Smooth the mixture into an even layer in the dish—this helps it cook uniformly and look just as inviting as it tastes.

Step 5: Bake to Perfection

Bake your casserole uncovered for 15 minutes, letting the sauce bubble and flavors marry. Then, pull the dish out and sprinkle the remaining cheddar cheese evenly over the top. Return it to the oven for another 10 minutes or until the cheese melts into a golden, gooey topping that’s impossible to resist.

Step 6: Serve Warm and Enjoy

Once it’s out of the oven, let your Broccoli Chicken Casserole Recipe rest just a few minutes—this helps everything set nicely. Then dig in while still warm, with every mouthful delivering creamy sauce, tender chicken, and crunchy broccoli in perfect harmony.

How to Serve Broccoli Chicken Casserole Recipe

A close-up of a white bowl with a black rim filled with rotini pasta that is light yellow and creamy in texture. Mixed in are bright green broccoli florets with a slightly roasted look and sliced brown mushrooms with a tender, cooked surface. The dish is sprinkled with cracked black pepper and some fresh green herbs. A silver fork rests inside the bowl. The bowl is placed on a white marbled surface. photo taken with an iphone --ar 4:5 --v 7

Garnishes

Sprinkle on a little freshly cracked black pepper or some chopped fresh parsley for a burst of color and freshness. A pinch of crispy breadcrumbs or even some chopped green onions can add a welcome crunch on top, making your casserole look as good as it tastes.

Side Dishes

This casserole is quite hearty, but pairing it with a simple green salad dressed with lemon vinaigrette keeps the meal light and balanced. Alternatively, a fresh tomato and cucumber salad with a sprinkle of feta cheese can add a bright, tangy contrast. Garlic bread or a warm crusty baguette also pairs wonderfully for soaking up any extra sauce.

Creative Ways to Present

Thinking outside the traditional casserole dish? Serve this as individual portions in small ramekins for an elegant touch at dinner parties. Or spoon it over a bed of fluffy rice or quinoa for a different twist on the classic. Even stuffing it into hollowed-out baked potatoes makes for a fun, comforting presentation your guests will love.

Make Ahead and Storage

Storing Leftovers

Leftover Broccoli Chicken Casserole Recipe keeps beautifully in an airtight container in the fridge for up to 3 days. Cover tightly to keep the cheesy top moist and the flavors vibrant. Just pop it back in the oven or microwave when you’re ready to enjoy.

Freezing

If you want to make this casserole ahead of time for busy nights, it freezes very well. Assemble it completely but hold off on adding the final layer of cheese to avoid over-browning. Freeze in an airtight container or wrapped tightly in foil for up to 2 months. When ready, bake straight from frozen, adding extra time as needed.

Reheating

To warm leftover casserole, cover loosely with foil and bake at 350°F until heated through—usually about 20 minutes depending on portion size. You can also reheat individual servings in the microwave, just be careful to cover loosely and stir midway to prevent drying out.

FAQs

Can I use other vegetables instead of broccoli?

Absolutely! Cauliflower, green beans, or even spinach can be beautiful substitutes or additions. Just make sure to adjust cooking times so the veggies stay tender but still have a little bite.

What type of chicken works best in this casserole?

Cooked, shredded chicken breasts or thighs work great here. Leftovers from a rotisserie chicken are perfect and save you cooking time, keeping the dish moist and flavorful.

Is there a way to make this recipe gluten-free?

Yes! Swap out regular flour for a gluten-free all-purpose blend when making the sauce, and use gluten-free pasta. Just ensure the stock and other ingredients are gluten-free as well.

Can I substitute the cheese?

While sharp cheddar is classic, feel free to use mozzarella for extra meltiness or pepper jack for a spicy kick. Mixing cheeses can also add exciting flavor dimensions.

How can I make this casserole dairy-free?

Use a plant-based milk alternative like almond or oat milk and substitute vegan butter or oil. There are also great dairy-free cheeses available that melt well to keep the dish creamy and delicious.

Final Thoughts

I can’t recommend this Broccoli Chicken Casserole Recipe enough if you’re craving a cozy, nourishing meal that’s packed with flavor but surprisingly simple to make. It’s a true crowd-pleaser with flexible ingredients and easy prep that fits into any weeknight or weekend dinner plans. So grab your skillet, chop that broccoli, and get ready for a dish that’s sure to become one of your all-time favorites in no time!