Introduction

This Healthier Broccoli Chicken Casserole is a comforting and nutritious meal perfect for family dinners. Packed with tender chicken, fresh broccoli, and a creamy, cheesy sauce, it balances wholesome ingredients with rich flavors for a satisfying dish.

A close-up view of a white ceramic pan filled with a baked pasta dish made of curly rotini pasta with a creamy light brown sauce mixing through. The dish is studded with green broccoli florets, sliced brown mushrooms with soft edges, and browned cubes of grilled chicken throughout. Melted cheese coats the ingredients giving a shiny finish while specks of black pepper and fresh chopped parsley are sprinkled on top. A woman's hand is holding a wooden spoon scooping a portion from the pan, showing the ingredients mixed together. The background surface is a white marbled texture. photo taken with an iphone --ar 4:5 --v 7

Ingredients

8 ounces uncooked pasta (whole-wheat rotini recommended)
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

Instructions

Step 1: Preheat your oven to 400°F.
Step 2: Cook the pasta in a large pot of generously salted boiling water until al dente. About 1 minute before the pasta is done, add the broccoli florets to the boiling water and stir to combine. Drain the pasta and broccoli together, then set aside.
Step 3: While the pasta cooks, heat the butter or olive oil in a large sauté pan over medium-high heat. Add the sliced onion and sauté for 3 minutes, stirring occasionally.
Step 4: Add the mushrooms and garlic to the pan. Continue sautéing for 5 more minutes, stirring occasionally, until the mushrooms are fully cooked.
Step 5: Sprinkle the flour evenly over the onion and mushroom mixture. Stir to combine and cook for 1 minute, stirring occasionally.
Step 6: Gradually add the stock while stirring to break up any flour clumps. Then pour in the milk, Dijon mustard, salt, and black pepper, stirring until the sauce is smooth.
Step 7: Bring the sauce to a simmer, then remove from heat and stir in 1 cup of the shredded cheddar cheese until melted and combined. Taste and adjust seasoning if necessary.
Step 8: In a large 9 x 13-inch baking dish, combine the cooked pasta, broccoli, mushroom sauce, and cooked chicken. Toss everything together until evenly mixed. Smooth the casserole into an even layer.
Step 9: Bake the casserole uncovered for 15 minutes. Remove from the oven, sprinkle the remaining cheddar cheese evenly on top, and bake for an additional 10 minutes or until the cheese is melted and bubbly.
Step 10: Serve warm, optionally garnished with fresh herbs or extra black pepper.

Tips & Variations

Use vegetable stock to make the casserole vegetarian (replace chicken with extra mushrooms or tofu).
Swap sharp cheddar for a milder cheese like mozzarella if you prefer a less intense flavor.
Add a pinch of smoked paprika or cayenne pepper to the sauce for a subtle kick.
Use leftover cooked chicken or rotisserie chicken to make preparation quicker.
For a crispier top, sprinkle breadcrumbs over the cheese before the final bake.

Storage

Store leftover casserole in an airtight container in the refrigerator for up to 3 days. To reheat, cover with foil and warm in a 350°F oven until heated through, about 15-20 minutes. You can also reheat individual portions in the microwave for 2-3 minutes.

How to Serve

A white bowl with a black rim holds cooked twisted pasta mixed with green broccoli florets and sliced brown mushrooms. The pasta is creamy and light yellow, with small bits of melted cheese and herbs sprinkled on top. The broccoli is bright green and slightly charred in places, while the mushrooms are golden brown with some darker grilled spots. A metal fork rests inside the bowl on the left side, touching the pasta. The bowl sits on a white marbled surface, with part of another similar bowl showing at the top right corner. photo taken with an iphone --ar 4:5 --v 7

Serve this delicious recipe with your favorite sides.

FAQs

Can I use frozen broccoli instead of fresh?

Yes, frozen broccoli works well. Thaw and drain it before adding to the pasta to avoid excess moisture in the casserole.

Is it possible to make this casserole dairy-free?

Absolutely. Substitute dairy milk with unsweetened almond or oat milk, use dairy-free butter or oil, and swap cheddar cheese for a plant-based alternative.