Chicken broccoli rice cheese casserole with mushroom sauce

I still catch the smell of my mom’s kitchen whenever I make this casserole — warm butter, toasted rice, and a mushroomy sauce that tastes like a cozy blanket. I learned to stir pots beside her when I was small, sneaking a spoonful of sauce every time she wasn’t watching (sorry, Mom). This chicken, broccoli, rice, and cheese casserole with mushroom sauce feels like that same comfort, but updated: a golden, bubbly top that crackles when you scoop, a creamy interior studded with bright green broccoli, and a rich mushroom sauce that makes every bite sing. It’s the kind of dinner that says, “You did good today,” whether you made it for a family night or just for yourself and leftovers.

Quick Facts

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

Why This Recipe is Awesome

This casserole combines creamy, cheesy comfort with a meaty, umami-packed mushroom sauce — it’s cozy and grown-up at the same time. The textures keep things interesting: tender chicken, slightly crisp broccoli, fluffy rice, and a golden crust. It’s forgiving, feeds a crowd, and reheats brilliantly. Plus, it smells like dinner triumph — buttery, garlicky, and mushroom-forward — which always wins me over.

Ingredients

For the Main Dish:

• 1 lb boneless skinless chicken breasts, cut into 1-inch pieces
• 2 cups cooked long-grain rice (about 1 cup uncooked)
• 3 cups broccoli florets (fresh or frozen)
• 2 cups shredded sharp cheddar cheese, divided
• 1/2 cup grated Parmesan cheese
• 2 tbsp butter
• 2 tbsp all-purpose flour
• 1 1/2 cups milk (whole or 2%)
• 1/2 tsp salt and 1/4 tsp black pepper, plus more to taste
• 1/2 tsp garlic powder and 1/2 tsp onion powder
• 1/2 cup panko breadcrumbs (optional, for topping)

For the Mushroom Sauce / Garnish:

• 8 oz mushrooms (cremini or button), sliced
• 2 tbsp olive oil or butter
• 1 clove garlic, minced
• 1/2 cup chicken broth
• 1/2 cup heavy cream or half-and-half
• 1 tbsp Worcestershire sauce (optional, for depth)
• Fresh parsley or chives for garnish

How I Make It

Step 1:

Preheat the oven to 375°F. Season the chicken with a little salt and pepper. Heat a large skillet over medium-high heat, add a drizzle of oil, and sear the chicken until it turns golden and gives off a savory, roasted smell — about 4–5 minutes. The sizzling sound makes me happier than it should. Transfer the chicken to a plate; it doesn’t need to be fully cooked through right now.

Step 2:

In the same skillet, melt 2 tbsp butter and whisk in 2 tbsp flour to make a roux. Let it bubble for 30 seconds, then slowly whisk in 1 1/2 cups milk until smooth. The mixture will thicken and smell vaguely toasty — that’s good. Stir in 1/2 tsp garlic powder, 1/2 tsp onion powder, 1/2 cup Parmesan, and half of the cheddar. Season with 1/2 tsp salt and 1/4 tsp pepper.

Step 3:

In a large bowl, combine the cooked rice, blanched or thawed broccoli, the seared chicken, and the cheese sauce. Stir until everything looks evenly coated — creamy and glossy. Spoon the mixture into a greased 9×13 baking dish, sprinkle the remaining cheddar and panko on top for a lovely golden finish.

Step 4:

Bake at 375°F for 25–30 minutes, until the edges bubble and the top browns to your liking. While the casserole bakes, make the mushroom sauce: heat 2 tbsp olive oil or butter in a skillet, add sliced mushrooms, and sauté over medium-high heat until they turn deep brown and give off a woodsy aroma — about 6–8 minutes. Toss in minced garlic for the last minute, deglaze with 1/2 cup chicken broth, then stir in 1/2 cup heavy cream and 1 tbsp Worcestershire. Let it simmer until slightly thickened, about 3–4 minutes. Taste and adjust salt and pepper.

Step 5:

Let the casserole rest for 5–10 minutes so it firms up slightly (that makes for neater slices). Spoon the warm mushroom sauce over individual portions, sprinkle with fresh parsley, and serve. Listen for the little crackle when you cut into it — that’s the sound of dinner done right.

Pro Tips

• Use day-old or chilled rice if you can — it keeps the casserole from getting gluey.
• If your broccoli tends to overcook, steam it for 2 minutes only so it stays bright green and slightly crisp in the bake.
• For extra golden edges, switch the oven to broil for 1–2 minutes at the end — watch it closely.
• No fresh mushrooms? Use 1 can (8 oz) sliced mushrooms drained and sautéed to concentrate flavor.

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

• Swap chicken for cubed firm tofu or cooked chickpeas to go vegetarian — expect a firmer texture and less savory depth.
• Use Greek yogurt thinned with a splash of milk instead of heavy cream for a lighter binder (tangier finish).
• For dairy-free: replace milk and cream with unsweetened oat or soy milk, use dairy-free cheese, and sub nutritional yeast for Parmesan.
• Make it gluten-free with a GF flour for the roux and gluten-free breadcrumbs or crushed cornflakes for the topping.

Variations & Tips

• Spicy kick: stir in 1–2 tbsp sriracha or chopped jalapeño into the cheese sauce.
• Kid-friendly: finely chop extra veggies (carrots, bell pepper) and hide them in the mix — they’ll blend into the creamy sauce.
• Mediterranean twist: swap cheddar for feta and add sun-dried tomatoes and olives.
• Herby upgrade: fold in 2 tbsp chopped pesto to the rice mixture before baking for a bright, savory lift.
• Crunchy top: swap panko for crushed fried onions for a classic comfort twist.
• Make it skillet-style: use a large ovenproof skillet to brown the top directly under the broiler for an extra-crispy edge.

FAQ (Frequently Asked Questions)

Can I make this ahead of time?

Yes! Assemble the casserole, cover, and refrigerate for up to 24 hours. Bake from cold, adding a few extra minutes to reach the bubbly stage. Store leftovers in the fridge for 3–4 days; reheat in a 350°F oven until warmed through.

Can I double the recipe?

Sure thing. Use two 9×13 dishes or a larger casserole pan. Increase bake time slightly (by 10–15 minutes) if you use a deeper dish; watch for bubbling edges and a golden top.

Can I substitute butter with oil?

Technically yes, but you’ll miss that buttery magic. Use ¾ the amount of oil as a swap (so 1 ½ tbsp oil for 2 tbsp butter).

How do I know it’s done?

Look for bubbly edges, a golden top, and hot filling. If you insert a knife into the center, it should come out hot to the touch. The chicken reaches safe internal temp when it hits 165°F.

What if I don’t have ingredient X?

Sub simple pantry staples: no Parmesan? Use extra cheddar or nutritional yeast. No panko? Use crushed crackers or tortilla chips for crunch.

How I Like to Serve It

I serve this casserole with a crisp green salad and a squeeze of lemon to cut the richness, or with buttery dinner rolls if I want total comfort. It works for weeknights and potlucks — it travels well and everyone gets seconds. For colder months, pair it with a malty brown ale or a light-bodied red; in spring, a chilled Sauvignon Blanc brightens the mushroom sauce.

Notes

• Store leftovers in an airtight container for up to 4 days. Reheat in a 350°F oven covered with foil to avoid drying out, about 15–20 minutes.
• Ensure chicken reaches a safe internal temp of 165°F before serving.

Final Thoughts

Closing: Give this casserole a try the next time you crave comfort with a little culinary swagger — then sit back and enjoy the applause (or the quiet satisfaction of eating the whole pan yourself). Now go impress someone — or just yourself — with your homemade masterpiece!