Chicken rice broccoli casserole with cheddar and mushrooms

My mom made a version of this casserole every chilly Sunday when I was a kid, and the house smelled like browned butter, garlic, and melting cheese before we even rang the dinner bell. I still remember that first spoonful — warm rice, tender chicken, bright green broccoli, and that rich cheesy sauce that somehow tasted like a hug. I recreate that feeling with this recipe, but I modernize it a bit (hello, sautéed mushrooms and a crunchy panko top). If you love cozy, slightly indulgent weeknight food that reheats like a dream, this one will become your go-to.

Quick Facts

• Yield: Serves 6
• Prep Time: 20 minutes
• Cook Time: 40 minutes
• Total Time: 60 minutes

Why This Recipe is Awesome

This casserole marries tender **chicken**, fluffy **rice**, crisp-tender **broccoli**, earthy **mushrooms**, and gooey **cheddar** into one pan of pure comfort. It gives you crunchy edges, a bubbly golden top, and a creamy interior that stands up to reheating. It’s also forgiving — a little messy, very satisfying, and so easy even a busy weeknight can handle it. Who doesn’t love crispy edges and that first cheesy pull?

Ingredients

For the Main Dish:

• 3 cups cooked shredded **chicken** (rotisserie works great)
• 3 cups cooked white rice (or brown rice for nuttier flavor)
• 2–3 cups broccoli florets, cut bite-size
• 8 oz cremini or button **mushrooms**, sliced
• 1 small yellow onion, finely chopped
• 3 cloves garlic, minced
• 3 tbsp unsalted butter
• 3 tbsp all-purpose flour
• 2 cups milk (whole or 2%)
• 1 cup low-sodium chicken broth
• 1/2 cup sour cream or plain Greek yogurt
• 1 tbsp Dijon mustard
• 2 tsp Worcestershire sauce (optional, for depth)
• 2 cups shredded sharp **cheddar**, divided
• 1/2 tsp paprika
• Salt and black pepper, to taste
• 1 cup panko breadcrumbs or crushed buttery crackers
• 2 tbsp melted butter (for the topping)

For the Sauce / Garnish (if applicable):

• Optional: extra 1/2 cup shredded **cheddar** to sprinkle before serving
• Optional: chopped parsley or chives for brightness

How I Make It

Step 1:

Preheat the oven to 375°F. While it warms, sauté the onion in 3 tbsp butter over medium heat until soft and fragrant — about 4 minutes. Toss in the minced garlic and sliced mushrooms, and cook until the mushrooms release their juices and start to brown, another 5–6 minutes. The kitchen will smell amazing — savory, slightly sweet, and earthy.

Step 2:

Sprinkle the sauté with 3 tbsp flour and stir for 1 minute to cook the raw flour taste away. Slowly pour in 2 cups milk and 1 cup chicken broth, whisking so the sauce stays smooth. Simmer until the sauce thickens and coats the back of a spoon. Stir in 1/2 cup sour cream, 1 tbsp Dijon, 2 tsp Worcestershire (if using), paprika, and half the cheddar until creamy and melty. Taste and season with salt and pepper.

Step 3:

In a big bowl, combine the sauce with the cooked rice, chicken, and blanched or steamed broccoli (blanch broccoli for 1–2 minutes in boiling water then shock in ice water so it stays bright). Fold gently so the rice keeps some texture — I like a few whole grains showing. The mixture should look glossy and smell rich and toasty from the mushrooms and cheddar.

Step 4:

Pour the mixture into a lightly greased 9×13-inch baking dish. Sprinkle the remaining cheddar on top, then mix the panko with 2 tbsp melted butter and scatter evenly. Bake at 375°F for 25–30 minutes until the top turns golden brown and the filling bubbles at the edges. Look for golden edges and bubbling center — that’s your cue.

Step 5:

Let the casserole rest for 5–10 minutes before serving so the sauce firms slightly and the slices hold together. Finish with chopped parsley or chives for color and a sprinkle of extra cheddar if you’re feeling indulgent. Serve warm and listen for those satisfied dinner-table hums.

Pro Tips

• Use a rotisserie chicken to save time and add flavor — it keeps the dish juicy.
• If your rice looks dry, add an extra 1/4 cup chicken broth to the filling before baking.
• For extra crispy panko, toast it in a skillet with a little butter until golden before topping.
• Swap 2 cups cooked rice for 3 cups cooked quinoa for a protein boost and nutty texture.

Common Mistakes to Avoid

• Skipping preheating: Classic rookie move. It changes texture and bake time.
• Overmixing: Leads to dense or chewy results. Mix until just combined.
• Guessing cook time: Always use visual cues or a timer, not just vibes.
• Overcrowding pans: Give your food some breathing room to crisp properly.

Alternatives & Substitutions

• Chicken ↔ tofu: Use 14 oz firm tofu, pressed and cubed, for a vegetarian swap. It changes texture but soaks up sauce nicely.
• Milk (dairy) ↔ unsweetened almond or oat milk: Keeps it lighter; use an extra tablespoon of flour if it seems thin.
• Sour cream ↔ Greek yogurt: Same tang, fewer calories.
• For dairy-free: Use plant-based milk and dairy-free cheddar, and replace butter with olive oil — flavor shifts slightly but still comforting.
• For gluten-free: Use a gluten-free flour blend for the sauce and gluten-free breadcrumbs or crushed gf crackers for topping.

Variations & Tips

• Spicy: Add 1 diced jalapeño to the sauté and 1/2 tsp cayenne to the sauce.
• Kid-friendly: Omit mushrooms and use mild cheddar; sneak extra veggies like sweet corn into the mix.
• Mediterranean twist: Swap cheddar for feta, add sun-dried tomatoes, and use oregano instead of paprika.
• One-pot shortcut: Cook rice and broccoli together in a large skillet, then finish in the oven in the same pan (reduce baking time by ~5 minutes).
• Make it lighter: Use cauliflower rice and reduced-fat cheese for a lower-carb version.
• Creative twist: Stir in 1/2 cup caramelized onions and a splash of balsamic for a sweet-savory note.

FAQ (Frequently Asked Questions)

Can I make this ahead of time?

Yes! Assemble the casserole, cover, and refrigerate up to 24 hours. Add 5–10 minutes to the bake time if cold straight from the fridge. Reheat leftovers at 350°F for 15–20 minutes until hot and bubbly.

Can I double the recipe?

Sure thing. Use a larger pan (like two 9x13s or a 13×9 plus a smaller one). Keep the bake temperature the same but add about 5–10 minutes to baking time for larger volumes.

Can I substitute butter with oil?

Technically yes, but you’ll miss that buttery magic. Use 3/4 the amount of oil (so for 3 tbsp butter, use about 2¼ tbsp oil) and consider a tiny pat of butter in the topping if you can.

How do I know it’s done?

Look for a golden-brown top, bubbling sauce at the edges, and a hot center. If you insert a knife into the middle it should come out warm to the touch.

What if I don’t have ingredient X?

Swap mozzarella or Monterey Jack for cheddar in a pinch. No panko? Crush buttery crackers or use crushed potato chips for a fun crunch.

How I Like to Serve It

I serve this casserole with a crisp green salad and a bright vinaigrette to cut the richness, and sometimes a pile of roasted carrots on the side. It works great for weeknight family dinners, a cozy potluck, or a casual Sunday supper. In winter, it feels like a warm blanket; in spring, I lighten it with extra lemony greens.

Notes

• Store leftovers covered in the fridge for up to 4 days. Reheat in a 350°F oven until warmed through.
• Make sure chicken reaches a safe internal temperature of 165°F before serving, and use cooked rice to avoid sogginess.

Final Thoughts

Closing: Now go impress someone — or just yourself — with your homemade masterpiece!