Cheesy Chicken Broccoli and Rice Casserole

This cheesy chicken broccoli and rice casserole is a complete meal in one dish, chicken, rice, broccoli, and a creamy cheese sauce that all cook together in the oven. No separate pots of rice, no steaming vegetables, everything goes in together.

The ingredient that surprised me most when I first made this: mayonnaise in the sauce. It sounds strange but it is what makes the sauce creamy without being watery, and it gives you that rich, almost velvety texture you get from restaurant casseroles. My family can’t tell it is in there, they just know this version tastes better than the standard cream of mushroom version.

Two things make or break this recipe: the foil has to be sealed tight for the first hour so the rice steams properly, and the rice needs to be checked at one hour before the cheese goes on. I’ll explain both.

Ingredients:

Chicken breasts (2 lbs, boneless skinless, cut into bite-sized pieces): Cook them in the skillet first before adding to the casserole. Raw chicken added directly releases too much liquid during baking and makes the rice cook unevenly. Pre-cooked rotisserie chicken works as a shortcut, use about 3 cups shredded and skip Step 1.

Uncooked long-grain white rice (1 1/2 cups): Long-grain only. Do not use instant rice or pre-cooked rice. Instant rice turns to mush because it is already partially cooked. Medium-grain works in a pinch but long-grain gives you the best separate-grain texture.

Frozen broccoli (12 oz bag): No need to thaw first. It goes in frozen and cooks perfectly in the casserole. Fresh broccoli cut into small florets works equally well. If using fresh, cut the pieces small so they soften fully during the hour of baking.

Cream of mushroom soup (2 cans, 10.75 oz each): Cream of chicken soup is a direct substitute if you prefer. The soup provides the liquid and body for the sauce along with the broth.

Chicken broth (2 1/2 cups): This is your rice cooking liquid. Do not reduce it or the rice will come out undercooked. Chicken stock works as a richer substitute.

Onion soup mix (1 packet): This is the seasoning base for the whole casserole. It does the work of multiple individual seasonings in one packet. I use Lipton. Do not skip it, the casserole tastes flat without it.

Mayonnaise (1/2 cup): This is the secret ingredient. It sounds unusual but it is what makes the sauce creamy and rich rather than watery. Full fat mayonnaise only, light mayo has more water and does not give you the same result.

Sharp cheddar and mozzarella (1 cup each): Half goes into the casserole before baking, half goes on top for the last 15 minutes. The sharp cheddar provides flavor, the mozzarella provides the stretchy melted cheese pull. Do not skip the two-cheese combination, using only cheddar gives you a greasier, less cohesive topping.

Garlic powder (1 tsp), dried thyme (1/2 tsp), salt (1/2 tsp), pepper (1/4 tsp): Season the chicken when you cook it. The thyme in the sauce is subtle but adds depth, do not increase it or it becomes overpowering.

Olive oil (2 tablespoons): For cooking the chicken. Avocado oil works as a substitute.

Chopped fresh parsley (optional): For garnish. Green onion works as well.

How Long Does This Keep in the Fridge?

Storage: Store leftovers in the refrigerator in an airtight container. It can be kept for up to  3-4 days.

When reheating, add a splash of chicken broth before warming, about 2 tablespoons per serving, or it comes out dry. Reheat in the oven at 350°F until warmed through, or microwave in 30-second increments.

To freeze: cool completely, wrap tightly, and freeze for up to 3 months. Thaw overnight in the refrigerator before reheating.

What Can You Add or Change in This Casserole?

Vegetables: Diced bell peppers, mushrooms, or green beans can go into the mixture in Step 4. Cook them in the skillet after the chicken first, raw vegetables added directly release water during baking and thin out the sauce.

Crunchy topping: Scatter crushed crackers, corn flakes, or panko over the cheese before the final 15 minutes uncovered. It adds a texture contrast the original does not have. My boys like it both ways.

Extra creaminess: Add 1/4 cup sour cream to the soup mixture in Step 3. The sauce comes out richer and slightly tangier. Do not go higher than 1/4 cup or the extra liquid throws off the rice-to-broth ratio.

Rotisserie chicken: Use about 3 cups shredded and skip Step 2 entirely. The final casserole is nearly identical and you save 15 minutes of active time.

Cream of chicken soup instead of mushroom: A direct swap at the same quantity. The flavor is milder and more neutral. If anyone in your family objects to mushroom, this is the obvious fix with no downside.

Medium-grain rice instead of long-grain: It works but the texture comes out stickier and the grains clump together more. Long-grain holds its shape better after an hour of baking

Questions About This Chicken and Rice and Broccoli Casserole:

Why is my rice still crunchy? 

Almost always the foil was not sealed tight enough or the oven temperature is slightly off. The rice needs a fully sealed steam environment to cook through. If you check at one hour and the rice is still crunchy, press the foil down firmly, make sure it is sealed at the edges, and bake another 15 minutes before checking again. Every oven is different, some take up to 90 minutes total.

Why do I need to cook the chicken first? 

Cooking the chicken beforehand ensures it is properly done and prevents the casserole from getting watery from raw chicken juices. It also gives the chicken better flavor and ensures it cooks evenly. The pre-cooked chicken also means you can use rotisserie chicken as a shortcut, add about 3 cups shredded directly to the sauce mixture in Step 4 and skip the skillet step entirely.

Can I use cooked rice instead of raw? 

Yes, with two adjustments: reduce the chicken broth by half to about 1 1/4 cups, and reduce total covered bake time to about 30 minutes. The casserole does not need all the liquid if the rice is not absorbing it from raw.

Can I use brown rice? 

Not in this recipe as written. Brown rice requires significantly more liquid and a longer cook time than white rice, about 90 minutes of covered baking at minimum. If you want to use brown rice, increase the chicken broth to 3 cups and plan for an additional 30 minutes of covered baking time before checking.

Why does my rice come out mushy?

 Usually instant or pre-cooked rice went in instead of raw long-grain white rice. Instant rice is already partially cooked and cannot survive another hour of baking without turning to paste. Make sure you are starting with raw long-grain white rice and not overcooking past the point where the rice is just tender.

Can I double this recipe? 

Yes, but use two 9×13 dishes rather than one larger pan. A deeper pan changes the cook time unpredictably and the rice in the center will lag behind the edges. Two standard pans side by side at the same temperature and time works reliably.

Can You Make This the Night Before?

Yes. Assemble everything through Step 4, cover tightly, and refrigerate for up to 24 hours. When ready to bake, pull it out while the oven preheats and add an extra 10 to 15 minutes to the covered bake time since it is starting cold. Everything else stays the same.