Creamy Chicken Breast Casserole with Broccoli and Rice

Chicken breast casserole is the kind of dish that turns a plain weeknight into something cozier. This version skips the canned soup and builds a creamy sauce from scratch, with tender broccoli and fluffy rice in every bite.

It bakes up bubbly and golden, with a layer of melted cheese on top that’s hard to resist. You’ll want to make it on repeat.

Why This Casserole Stays in My Rotation

The chicken stays juicy because we give it a quick sear first, then it finishes cooking gently in the oven. The from-scratch sauce tastes clean and rich, nothing like a can.

Leftovers are even better the next day, and it’s a complete meal in one dish. No extra pots to wash.

Ingredients

• 1.5 lbs boneless skinless chicken breasts (about 3 medium): sliced into thick strips after searing
• 3 cups fresh broccoli florets: cut into bite-sized pieces
• 2 cups cooked white rice: from about 1 cup uncooked
• 3 tbsp unsalted butter: for the roux
• 1 small yellow onion, diced
• 2 cloves garlic, minced
• 3 tbsp all-purpose flour
• 2 cups chicken broth: low-sodium is best
• 1 cup whole milk: or 2% for a lighter sauce
• 1 tsp Dijon mustard: for a subtle tang
• 1.5 cups shredded sharp cheddar cheese: divided
• Salt and black pepper

Variations / Substitutions

• Swap broccoli for cauliflower or frozen peas: keep the pieces small so they cook through during baking
• Use rotisserie chicken: shred it and skip the searing step to save 10 minutes
• Try brown rice: cooked brown rice has a chewier texture and adds a little more fiber
• Dairy-free: use olive oil instead of butter, a thick unsweetened plant milk, and a dairy-free cheese that melts well
• Lighter cheese: a mix of mozzarella and a little Parmesan still gives you a golden top with less sharpness

If you love creamy chicken and rice together, you might also like my Skillet Chicken and Rice.

How to Make Creamy Chicken Breast Casserole

Step 1: Sear the Chicken

Preheat your oven to 375°F (190°C). Season the 1.5 lbs chicken breasts on both sides with a generous pinch of salt and pepper. Heat a drizzle of oil in a large skillet over medium-high heat. Once the oil shimmers, lay the chicken in the pan and sear for about 4 minutes per side. The surface should be lightly golden but the center will still be raw; that’s exactly what you want. Transfer the chicken to a cutting board and set aside.

The outside of the chicken will take on a pale bronze color, and the pan will have a few browned bits ready to flavor the sauce.

Step 2: Sauté the Onion and Garlic

Lower the heat to medium and melt 3 tbsp of butter in the same skillet. Toss in the diced onion and cook, stirring often, for 3 to 4 minutes, until it softens and turns translucent. Add the minced garlic and let it sizzle for 30 seconds more, just until fragrant.

The onion will sweat down and the garlic smell will fill the kitchen, a good sign the base for your sauce is building.

Step 3: Build the Cream Sauce

Sprinkle 3 tbsp of flour over the onion mixture and whisk constantly for 1 minute to cook out the raw flour taste. Slowly pour in the 2 cups of chicken broth while whisking, then add the 1 cup of milk and the 1 tsp of Dijon mustard. Keep whisking as the sauce comes to a gentle simmer. Let it bubble for 5 to 7 minutes, stirring occasionally, until it coats the back of a spoon.

The sauce will thicken and turn silky. At this point, stir in half of the shredded cheddar (about 3/4 cup) and a few grinds of black pepper. Taste and adjust the salt, keeping in mind the cheese adds saltiness too.

Step 4: Assemble the Casserole

Spread the 2 cups of cooked rice evenly in a 9-by-13 inch baking dish. Scatter the 3 cups of broccoli florets over the rice. Slice the seared chicken breasts into thick strips and arrange them on top. Pour the warm cheese sauce over everything, nudging the pieces gently so the sauce settles into the nooks. Scatter the remaining shredded cheddar over the top.

Bake, uncovered, for 25 to 30 minutes. The sauce will bubble around the edges, the cheese on top will melt into a golden sheet, and a fork inserted into the thickest chicken strip should meet no resistance.

Step 5: Scoop and Serve

Let the casserole rest for about 5 minutes so the sauce sets up just enough not to run everywhere. Use a large spoon to scoop generous portions onto plates, making sure each serving gets some of that golden, cheesy top and a good mix of rice, broccoli, and chicken. Serve while it’s still hot.

Tips for the Best Casserole

• Give the chicken a quick sear even if you’re in a hurry. Those browned bits on the bottom of the skillet build a ton of flavor in the sauce.
• Keep the broccoli florets on the smaller side so they become tender during the bake without going mushy.
• If the top isn’t as brown as you like, switch the oven to broil for the final 2 minutes. Watch it closely so the cheese doesn’t burn.
• Rest the casserole before serving. That short wait helps the sauce thicken so you get neat scoops instead of a puddle.
• You can swap in leftover cooked chicken to save time. Skip the searing step and stir the shredded chicken right into the sauce before pouring it over the rice.

Bake times by dish size:

Storing Leftovers

Refrigerate leftovers in an airtight container for up to 4 days. The rice soaks up the sauce overnight and tastes even richer the next day.

Reheat individual portions in the microwave or place the whole casserole back in a 350°F (175°C) oven until warmed through, about 15 minutes.

What to Serve with Chicken Breast Casserole

A crisp green salad with a sharp lemon vinaigrette cuts through the richness nicely. Roasted asparagus with a little olive oil and salt adds a fresh vegetable that doesn’t compete with the creamy sauce. Warm garlic bread on the side is never a bad idea when there’s extra cheese sauce to mop up.

Frequently Asked Questions

Can I use frozen broccoli?

Yes. Thaw the frozen broccoli first and pat it dry with paper towels so extra water doesn’t thin the sauce.

I only have chicken thighs. Can I use those?

Boneless, skinless chicken thighs work well here. Sear them just like the breasts and check that they reach 165°F (74°C) in the oven.

Can I assemble this casserole ahead of time?

Assemble it without baking, cover, and refrigerate for up to 24 hours. When you’re ready, bake as directed but add about 10 minutes to the baking time to account for the chilled dish.

What if I don’t have cooked rice?

Start a pot of rice as the very first thing you do, and it will be ready by the time you need to assemble the casserole.

Creamy Chicken Breast Casserole Recipe

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Prep Time 20 minutes mins

Cook Time 30 minutes mins

Total Time 50 minutes mins

Servings: 6 servings

Calories: 470

Ingredients Method Notes

Ingredients

  

• 1.5 lbs boneless skinless chicken breasts (about 3 medium)
• 3 cups fresh broccoli florets
• 2 cups cooked white rice
• 3 tbsp unsalted butter
• 1 small yellow onion, diced
• 2 cloves garlic, minced
• 3 tbsp all-purpose flour
• 2 cups chicken broth
• 1 cup whole milk
• 1 tsp Dijon mustard
• 1.5 cups shredded sharp cheddar cheese
• Salt and black pepper

Method

 

1. Preheat oven to 375°F (190°C). Season chicken with salt and pepper, then sear in a hot oiled skillet for about 4 minutes per side until golden. Remove and set aside.
2. Melt butter in the skillet, add onion and cook 3-4 minutes until soft. Add garlic and cook 30 seconds.
3. Whisk in flour and cook 1 minute. Gradually whisk in broth, milk, and Dijon. Simmer 5-7 minutes until thickened. Stir in half the cheese and season with pepper and salt.
4. Spread rice in a 9×13 dish, top with broccoli, slice chicken and arrange on top. Pour sauce over, sprinkle remaining cheese. Bake 25-30 minutes until bubbly and golden.
5. Rest 5 minutes, then scoop onto plates and serve hot.

Notes

Let the casserole rest a few minutes before serving so the sauce thickens slightly. The chicken is safe to eat when an instant-read thermometer inserted in the thickest strip reaches 165°F (74°C).