
This comforting broccoli chicken casserole quickly became a weeknight favorite in my kitchen for its creamy texture and wholesome ingredients. It brings together tender chicken and vibrant broccoli in a cheesy mushroom sauce, all layered over your favorite pasta for a filling and healthier family dinner.
I first whipped this up on a rainy Sunday when we wanted something cozy yet light. My kids especially love that golden layer of bubbly cheddar on top and it has now become our go to answer for “What’s for dinner” requests.
Ingredients
- Uncooked pasta: I like whole wheat rotini for a nutty flavor and extra fiber Look for firm pasta that holds up to baking
- Fresh broccoli florets: These add crunch and color Choose florets with tight green tops and no yellowing
- Butter or olive oil: I switch between the two depending on how light I want it Both help soften the aromatics
- Small white onion: Thinly sliced for sweetness Look for onions without blemishes or sprouts
- Baby bella mushrooms: These give a rich earthy depth Pick ones that are firm and free of dark spots
- Garlic: Freshly minced for punchy flavor The cloves should be plump and not shriveled
- Flour: Helps thicken the sauce Go for all purpose and sift if it clumps
- Chicken or vegetable stock: Delivers savory flavor Use a low sodium variety so you can control seasoning
- Milk: This makes the sauce creamy Opt for whole milk or a mix of 2 percent and half and half for richness
- Dijon mustard: A spoonful for tang and brightness Choose a smooth classic Dijon
- Fine sea salt: For seasoning
- Freshly cracked black pepper: For subtle heat and depth
- Sharp cheddar cheese: Melts beautifully and adds bold flavor Freshly shred a block for best melt
- Cooked chicken: Diced or shredded Use leftovers or a rotisserie chicken for convenience
Step-by-Step Instructions
- Prep and Preheat:
- Heat your oven to four hundred degrees Fahrenheit to get ready for baking
- Boil Pasta and Broccoli:
- Cook the pasta in a large pot of salted boiling water until almost tender about one minute before done add the broccoli This lets everything finish cooking together and saves washing another pan Drain well
- Sauté Vegetables:
- Heat butter or oil in a big pan over medium high Add onions and keep them moving for three minutes so they become translucent Toss in mushrooms and garlic Stir and cook until mushrooms brown and their moisture cooks off about five minutes
- Build the Sauce:
- Sprinkle flour all over the sautéed veggies Stir constantly letting the flour coat everything and cook for a minute Pour in the stock slowly stirring until smooth Add milk Dijon salt and pepper and mix well Heat until the sauce barely simmers then take off the heat and stir in half the shredded cheese Let it melt completely for a silky finish Taste and adjust seasoning
- Assemble the Casserole:
- Combine the drained pasta broccoli chicken and mushroom sauce in a large baking dish Toss so everything is evenly coated and nestled together Smooth the top with a spoon
- Bake and Finish:
- Bake uncovered for fifteen minutes so it heats through Take it out and sprinkle over the rest of the cheddar cheese Return to the oven for ten minutes or until the cheese bubbles and turns golden brown
- Serve and Enjoy:
- Serve warm with extra pepper or fresh chopped herbs if you like

Mushrooms are my favorite part of this recipe I find their flavor really intensifies as they bake into the sauce My daughter always sneaks extra broccoli on her plate because it tastes so good with the cheesy topping I love that this dish brings us together around the table and makes everyone happy
Storage Tips
Once completely cooled transfer the casserole to airtight containers It will keep well in your fridge for up to four days For longer storage freeze individual portions wrapped tightly and tucked in a freezer bag When ready to eat thaw overnight and reheat gently in the oven or microwave until piping hot
Ingredient Substitutions
You can swap in any pasta that holds sauce well such as penne or shells If you want to make this vegetarian use vegetable stock and skip the chicken instead add extra mushrooms or even some cooked chickpeas for protein Feel free to use frozen broccoli as a substitute for fresh just let it thaw and blot excess moisture first
Serving Suggestions
This casserole stands on its own for dinner but I sometimes serve it with a crunchy green salad or sliced tomatoes for extra freshness For gatherings try sides like roasted carrots or a slice of rustic bread to mop up any creamy sauce left on the plate

Cultural Context
Casseroles like this have always been comfort classics in American kitchens especially for busy families looking for warm nourishing meals This version gives a nod to tradition but lightens things up by skipping canned soups and highlighting the fresh veggies I believe the best casseroles are ones that bring everyone together around the table
Frequently Asked Questions
- → Can I use frozen broccoli instead of fresh?
Yes, frozen broccoli florets can be substituted. Thaw and drain them before adding to the dish.
- → What kind of pasta works best?
Any pasta can be used—whole-wheat, gluten-free, or traditional. Choose shapes that hold sauce well, like rotini or penne.
- → Can this dish be prepared in advance?
Absolutely—assemble everything ahead and refrigerate. Bake just before serving for best texture and freshness.
- → Is there a vegetarian option?
Omit the chicken and use vegetable stock for a hearty, meatless version packed with vegetables and cheese flavors.
- → How should leftovers be stored?
Keep leftovers covered in the refrigerator for up to three days. Reheat in the oven or microwave until warmed through.