Cheesy Broccoli Rice Casserole

The first thing I look for when this comes out of the oven is a gentle bubble around the edges, not a dark crust across the whole top. That tells…

By Willow • October 14, 2026 • Reading time: 9 min

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The first thing I look for when this comes out of the oven is a gentle bubble around the edges, not a dark crust across the whole top. That tells me the creamy middle is hot and the cheddar has melted without drying out. I make this cheesy broccoli rice casserole when I want a comforting, scoopable dinner that brings rice and vegetables together in one baking dish.

Cooking the long-grain rice separately gives it a head start before it meets the creamy mixture. Condensed cream of mushroom soup gives the casserole body, while milk and sour cream loosen it into a sauce that coats the rice and broccoli instead of disappearing into them.

Sharp cheddar runs through the casserole and melts over the top, so each spoonful has a little richness and a savory bite. Let it settle after baking, then serve while the edges are still bubbling and the center is soft and creamy.

Why Frozen Broccoli Can Make This Casserole Watery

Thawed broccoli holds more water than it looks like it should. That extra moisture doesn’t vanish in the oven; it gets released into the soup mixture and can leave the rice sitting in a loose, wet sauce. Since the broccoli is already thawed before it goes into the dish, draining it well is part of getting the casserole’s texture right.

Press the florets gently in a colander rather than squeezing them hard. The aim is to remove surface water while keeping the pieces intact. Big florets should be cut into bite-size pieces so they mix evenly through the rice and don’t leave one serving with all the broccoli.

The sauce should coat the rice and vegetables before baking, not look like a thin soup. Once the casserole heats, the rice and cheese help the mixture come together, and the bubbling edges give you a clear sign that it’s hot through. Keeping excess water out at the start lets the finished casserole stay creamy instead of pooling liquid on the plate.

What the Creamy Base and Sharp Cheddar Each Bring

• Long-grain white rice — Its separate stovetop cooking keeps the grains distinct before they go into the creamy mixture. Rinsing it first clears excess surface starch, which helps prevent a sticky, clumped result. Brown rice isn’t a direct swap because it needs a different cooking time and liquid ratio.
• Condensed cream of mushroom soup — This is the base that gives the casserole its savory, thick texture. A different soup would change the flavor and may change how loose the mixture feels, so stick with cream of mushroom for the intended result.
• Whole milk and sour cream — Milk loosens the condensed soup enough to coat the rice, and sour cream adds a gentle tang and a fuller texture. There isn’t a like-for-like dairy-free swap among the ingredients here; changing both would mean changing the character of the sauce.
• Sharp cheddar — Sharp cheddar gives the mild rice and broccoli a more pronounced savory edge. For the smoothest melt, shred a block of cheddar yourself; packaged shredded cheddar is convenient, though its coating can leave the sauce a little less silky.
• Yellow onion — Finely chopped onion softens in butter and brings a mellow savory note through the sauce. Cutting it small matters: large pieces stay more noticeable instead of blending into the creamy base.

Cook the Rice and Build the Casserole in Separate Stages

Simmer the Rice Until the Water Is Absorbed

Combine the rinsed rice, water, and kosher salt in a 2-quart saucepan, then bring it to a boil over medium-high heat. Cover the pan, reduce the heat to low, and simmer for 15 to 18 minutes. The water should be absorbed before you take the pan off the heat. Let the rice rest, covered, for 5 minutes, then fluff it with a fork.

Drain the Broccoli and Prepare the Dish

Let the thawed broccoli drain in a colander and press it gently to remove excess water. Cut any extra-large florets into bite-size pieces; the smaller pieces will be easier to fold through the rice. Coat a 9×13-inch baking dish with nonstick cooking spray. Keep it nearby while you mix the sauce so the casserole can go straight into the oven once assembled.

Soften the Onion and Mix the Cheesy Sauce

Melt the butter in a 10-inch skillet over medium heat, then add the finely chopped onion. Cook for 4 to 5 minutes, stirring occasionally, until softened; the onion should look tender rather than browned. In a large bowl, whisk together the condensed soup, milk, sour cream, and black pepper. Stir in the cooked onion and 1 1/2 cups of the cheddar until the cheese is distributed through the sauce.

Fold, Top, and Bake Until the Edges Bubble

Fold the cooked rice and broccoli into the soup mixture until everything is evenly coated, then spread it in the prepared dish. Sprinkle the remaining 1/2 cup cheddar over the top. Bake uncovered at 350°F for 25 to 30 minutes, until the edges are bubbling and the cheese is melted. Let the casserole rest for 10 minutes before serving so the creamy center can settle.

Small Changes That Shift the Texture Without Losing the Casserole

Questions That Come Up When Making Broccoli Rice Casserole

Cheesy Broccoli Rice Casserole

Cheesy broccoli rice casserole combines tender long-grain rice and broccoli in a creamy mushroom sauce, topped with sharp cheddar. Bake it uncovered until bubbling around the edges and the cheese is melted.

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Prep Time 15 minutes mins

Cook Time 53 minutes mins

Resting time 15 minutes mins

Total Time 1 hour hr 23 minutes mins

Servings: 8 servings

Course: Side Dish

Cuisine: American

Calories: 360

Ingredients Equipment Method Notes

Ingredients

  

For the rice

• 1 cup long-grain white rice rinsed
• 2 cups water
• 0.5 teaspoon kosher salt

For the broccoli

• 1 package (16 oz) frozen broccoli florets thawed

For the casserole

• 1 nonstick cooking spray
• 2 tablespoons unsalted butter
• 1 yellow onion small, finely chopped
• 1 can (10.5 oz) condensed cream of mushroom soup
• 1 cup whole milk
• 0.5 cup sour cream
• 0.25 teaspoon black pepper
• 2 cups sharp cheddar cheese shredded, divided

Equipment

• 1 2-quart saucepan
• 1 9x13-inch baking dish
• 1 10-inch skillet

Method

 

Prepare the oven

1. Heat the oven to 350°F.

Cook the rice

1. Combine the rice, water, and salt in a 2-quart saucepan.
2. Bring the mixture to a boil over medium-high heat.
3. Cover, reduce the heat to low, and simmer for 15 to 18 minutes, until the water is absorbed.
4. Remove the pan from the heat and let the rice rest, covered, for 5 minutes.
5. Fluff the rice with a fork.

Prepare the broccoli

1. Drain the thawed broccoli in a colander, pressing gently to remove excess water.
2. Chop any extra-large broccoli florets into bite-size pieces.

Make the casserole

1. Coat a 9x13-inch baking dish with nonstick cooking spray.
2. Melt the butter in a 10-inch skillet over medium heat.
3. Add the onion and cook for 4 to 5 minutes, stirring occasionally, until softened.
4. Whisk together the soup, milk, sour cream, and black pepper in a large bowl.
5. Stir in the cooked onion and 1 1/2 cups of the cheddar.
6. Fold the cooked rice and broccoli into the soup mixture.
7. Spread the mixture evenly in the prepared dish.
8. Sprinkle with the remaining 1/2 cup cheddar.
9. Bake uncovered for 25 to 30 minutes, until bubbling around the edges and the cheese is melted.
10. Let the casserole rest for 10 minutes before serving.

Notes

For the best texture, press excess water from the thawed broccoli before mixing it in. Refrigerate leftovers for up to 3–4 days; freezer-friendly. For a gluten-free option, use a gluten-free condensed cream of mushroom soup.