Creamy Weeknight Chicken Broccoli Casserole

This chicken broccoli casserole checks all the boxes for a dinner you can count on: creamy, cheesy, and loaded with tender chicken and broccoli in one skillet. The whole thing comes together fast, without a single can of soup.

Instead of canned shortcuts, you make a simple sauce from scratch while the chicken cooks. The result tastes fresh and real, and it leaves you with one pan to wash instead of a counter full of dishes.

Why This Casserole Always Works

The sauce is rich but not heavy. A little chicken broth cuts the richness of the cheese, and the sauce stays silky without being gloopy.

The broccoli holds its own. A quick blanch keeps it bright green and just tender, so it doesn’t turn to mush in the oven.

Everything bakes in one skillet. You cook the chicken, make the sauce, and bake all in the same pan, which means fewer dishes and more time to relax.

Ingredients

• 1 lb boneless, skinless chicken breasts or thighs, cut into bite-size pieces: thighs stay extra juicy, but breasts work just as well
• 3 cups broccoli florets (from about 1 small head): cut them into similar sizes so they blanch evenly
• 1 1/2 cups shredded sharp cheddar cheese: freshly shredded melts smoother than the bagged stuff
• 1/4 cup unsalted butter, divided: you’ll use half for the chicken and half for the sauce
• 1/4 cup all-purpose flour
• 1 1/2 cups whole milk: 2% works, but whole milk makes the sauce noticeably creamier
• 1/2 cup chicken broth
• 1/2 tsp garlic powder
• 1/2 tsp onion powder
• 1/2 tsp fine sea salt, plus more for the chicken and blanching water
• 1/4 tsp black pepper
• 1 tsp Dijon mustard (optional): adds a tiny kick of tang without tasting mustardy
• 1/2 cup panko breadcrumbs (optional): for a crisp, golden topping
• 1 tbsp melted butter (optional): just if you are using the panko topping

Variations and Substitutions

• Swap the protein: Use leftover shredded turkey or rotisserie chicken. Skip the chicken-cooking step and stir about 2 cups of shredded cooked chicken into the sauce.
• Try a different cheese: Gruyère, Monterey Jack, or a mild gouda all melt beautifully. Avoid pre-shredded cheese, which can make the sauce grainy.
• Make it gluten-free: Use a cup-for-cup gluten-free flour blend in the sauce and gluten-free panko for the topping.
• Add a little heat: Stir a pinch of cayenne into the sauce or a few dashes of hot sauce.
• Go low-carb: Skip the panko topping and serve the casserole over cauliflower rice instead of any starch.

For a creamier, no-cook version, try my Slow Cooker Chicken and Broccoli Alfredo.

How to Make Creamy Weeknight Chicken Broccoli Casserole

Step 1: Cook the Chicken

Preheat your oven to 375°F (190°C). In a large oven-safe skillet (10 inches works best), melt 2 tablespoons of the butter over medium-high heat. While the butter foams, season the chicken pieces with a pinch of salt and a few grinds of black pepper. Add the chicken in a single layer and cook, stirring occasionally, until golden on the outside and no longer pink inside, 6 to 8 minutes. Transfer the cooked chicken to a plate and set it aside.

The chicken should have some browning, which adds flavor to the whole dish. If your skillet isn’t big enough to give each piece a little room, cook in two batches so the chicken sears instead of steaming.

Step 2: Blanch the Broccoli

While the chicken cooks, bring a medium pot of generously salted water to a boil. Drop in the 3 cups of broccoli florets and cook until they turn bright green and are just tender when pierced with a fork, 2 to 3 minutes. Drain immediately and rinse under cold water to stop the cooking. Shake the colander well to remove any extra water.

You don’t want the broccoli fully cooked here—it will finish in the oven. Getting rid of as much water as possible now keeps the casserole from turning watery later.

Step 3: Make the Cheese Sauce

Return the skillet to the stove and lower the heat to medium. Melt the remaining 2 tablespoons of butter. Sprinkle in the 1/4 cup of flour and whisk constantly for about 1 minute, until the mixture looks like wet sand and smells a little nutty. Slowly pour in the 1 1/2 cups milk and 1/2 cup chicken broth, whisking as you go to avoid lumps. Bring the sauce to a gentle simmer and cook, whisking often, until it thickens enough to coat the back of a spoon, 3 to 4 minutes.

Take the skillet off the heat, then stir in 1 cup of the shredded cheddar, the garlic powder, onion powder, the 1/2 teaspoon of salt, the pepper, and the Dijon if you are using it. Keep stirring until the cheese melts completely and the sauce is smooth. Taste and add more salt if it needs it.

Step 4: Assemble the Casserole

Add the cooked chicken and blanched broccoli back into the skillet with the cheese sauce. Fold everything together gently so each piece gets coated. If you want a crispy top, mix the 1/2 cup panko breadcrumbs with the 1 tablespoon of melted butter in a small bowl. Smooth the top of the casserole, then scatter the remaining 1/2 cup of cheddar over it. If using, sprinkle the buttered panko evenly over the cheese.

If you do not own an oven-safe skillet, transfer the whole mixture to a greased 9×13-inch baking dish before adding the toppings. The dish will be full but not overflowing.

Step 5: Scoop and Serve

Slide the skillet (or baking dish) onto the middle rack of the preheated oven and bake until the casserole is hot all the way through and the top is golden and bubbling around the edges. Start checking at 20 minutes; it could take up to 25 depending on your oven. Let the casserole rest for 5 minutes after you pull it out—it will set up a little and be easier to serve.

Carry the skillet right to the table and scoop generous spoonfuls onto plates. A final crack of black pepper on top never hurts.

Tips for the Best Casserole

• Shred your own cheese. Pre-shredded cheese is coated with starches that can make the sauce grainy. A block of sharp cheddar grated at home melts into a silky sauce.
• Don’t skip the blanch. It might feel like an extra step, but it keeps the broccoli from releasing water into the casserole as it bakes, which would thin out the sauce.
• Let it rest. Those 5 minutes after baking let the sauce set up just enough so each spoonful holds its shape instead of running all over the plate.
• If you’re starting with cooked chicken, use 2 to 2 1/2 cups shredded and stir it into the sauce in Step 4. You can skip Step 1 entirely.

Baking times can shift depending on what you bake in.

Storing Leftovers

Keep any leftover casserole in a sealed container in the fridge for up to 4 days. Reheat single portions quickly in the microwave. To rewarm the whole dish, cover with foil and bake at 350°F (175°C) for 15 to 20 minutes, until heated through.

What to Serve With Chicken Broccoli Casserole

This casserole is a meal on its own, but a bright, tangy side cuts through the richness beautifully. A simple green salad with a lemon vinaigrette is my usual pairing—the acid wakes everything up. If you want something warm, roasted carrots or a side of steamed green beans work well, too.

Frequently Asked Questions

Can I use frozen broccoli?

Yes. Thaw the frozen broccoli completely and press out as much extra water as you can with paper towels, then skip the blanching step and add it straight to the casserole.

Can I assemble this ahead of time?

You can. Assemble the casserole through Step 4, cover it, and refrigerate for up to 24 hours. When you’re ready to bake, add 10 to 15 minutes to the baking time since it will start cold.

What other cheeses work here?

Gruyère, fontina, or a soft Monterey Jack all melt well and taste great. Steer clear of very hard cheeses like Parmesan as the main cheese because they don’t give the same creamy texture.

Is there a dairy-free version?

You can make a dairy-free sauce by swapping the butter for olive oil, using unsweetened almond or oat milk, and a good melty plant-based cheddar shred. The texture will be a little different, but it still comes together nicely.