There’s something special about pulling a warm, bubbling casserole from the oven—
the kind of meal that feels cozy, familiar, and perfect for a busy night.
This lighter Broccoli Chicken Casserole delivers all that comfort,
but with simple, wholesome ingredients and a creamy sauce made from scratch.
As it bakes, the kitchen fills with the savory smell of cheddar, mushrooms,
and tender broccoli, inviting everyone toward the table.
Families love how hearty and satisfying it is,
and you’ll love that it comes together with pantry basics and leftover chicken.
A warm, comforting dinner that still feels fresh and nourishing—
just the kind of meal you’ll want to make again and again.
For the Broccoli Chicken Casserole
- Pasta – You’ll need 8 ounces of uncooked pasta. Whole-wheat rotini works great, but any pasta shape you like will do.
- Broccoli – One large head, cut into bite-sized florets (about 1 pound). Fresh or thawed frozen florets both work.
- Butter or Olive Oil – Used to sauté the veggies and build the base of the sauce.
- White Onion – Thinly sliced; adds sweetness and depth once sautéed.
- Baby Bella (Cremini) Mushrooms – They bring savory, earthy flavor and help give the sauce richness.
- Garlic – Four cloves, minced. This is where a lot of the flavor kicks in.
- Flour – Helps thicken the creamy sauce so it coats the pasta and broccoli perfectly.
- Chicken or Vegetable Stock – Adds moisture and rounds out the sauce without making it heavy.
- Milk – Makes the sauce creamy while still keeping things on the lighter side.
- Dijon Mustard – A small amount makes the sauce more complex and cuts through the richness.
- Fine Sea Salt – Seasons the sauce and brings everything together.
- Black Pepper – Freshly cracked for the best flavor.
- Sharp Cheddar Cheese – Two cups total (8 ounces), divided. Some melts into the sauce; the rest goes on top for that cheesy baked finish.
- Cooked Chicken – Two cups, diced or shredded. Great for using leftovers or rotisserie chicken.
Broccoli & Chicken Pasta Bake (Lightened-Up Version)
A cozy, satisfying casserole featuring pasta, chicken, broccoli, and a smooth cheddar-mushroom sauce.
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Servings: 8
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Ingredients
- 8 ounces uncooked pasta (whole-wheat rotini was used)
- 1 large head of broccoli, cut into bite-size pieces (about 1 pound florets)
- 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
- Preheat your oven to 400°F.
- Cook the pasta:
Bring a large pot of salted water to a boil and cook the pasta until just al dente. During the final minute of cooking, add the broccoli directly to the pot. Drain both together and set aside. - Prepare the sauce:
Warm the butter or oil in a large sauté pan over medium-high heat. Add the onion and cook for about 3 minutes. Stir in the mushrooms and garlic, cooking for another 5 minutes or until the mushrooms soften. - Thicken the mixture:
Sprinkle the flour over the vegetables and mix well. Let it cook for 1 minute. Pour in the stock, stirring until the mixture smooths out. Add the milk, Dijon mustard, salt, and pepper. Keep cooking until the sauce begins to simmer. Remove from heat and melt in 1 cup of the cheddar. Adjust seasoning if desired. - Assemble the casserole:
In a 9×13-inch baking dish, combine the pasta, broccoli, sauce, and chicken. Mix until evenly coated and spread into a flat layer. - Bake:
Bake uncovered for 15 minutes. Remove the dish from the oven, scatter the remaining cheddar over the top, and return it to the oven for 10 more minutes, or until the cheese melts thoroughly. - Serve:
Enjoy warm. Fresh herbs or a little extra cracked pepper make great finishing touches.
- Pasta: Any variety works—traditional, whole-wheat, egg-based, gluten-free, or alternative-grain.
- Broccoli: You can swap in 1 pound thawed frozen broccoli florets if needed.
- Can I use frozen broccoli instead of fresh?
Absolutely! Frozen broccoli works fine — just make sure it’s fully thawed and really well-drained before adding it to the casserole. Too much moisture can make it a bit watery, and nobody wants a soggy pasta bake.
- How do I stop the pasta from getting mushy?
The trick is to cook the pasta just shy of al dente. It’ll continue to cook in the oven with the sauce and broccoli, so leaving it slightly firm keeps everything perfectly textured.
- Can I prep this ahead of time?
Yes! You can assemble the whole casserole, cover it tightly, and pop it in the fridge. When you’re ready to bake, let it sit at room temperature for a few minutes and then bake as usual. Perfect for busy weeknights or making ahead for meal prep.
- How do I avoid a watery casserole?
Two things usually cause that: veggies with too much water, and sauce that’s too thin. Pat the broccoli dry, and make sure your sauce simmers until thick before mixing everything together. Done and done.
- Can I use leftover or rotisserie chicken?
Totally. Pre-cooked chicken saves time and still tastes amazing. Just dice or shred it and stir it in with the pasta, broccoli, and sauce. Shortcut = weeknight hero.
