Cheesy Mushroom Rice Casserole
Creamy cheesy comfort ready for the holiday table.

Nothing draws you into the kitchen, wanting you to embrace the warmth emanating from the oven, quite like a creamy and cheesy casserole. This Cheesy Mushroom Rice Casserole is a complex side dish perfect for the holidays. A from-scratch cheese sauce fortified with savory earthy elements is the flavorful powerhouse that coats every grain of comforting carby rice for a dish that may outshine your tried-and-true recipe staples.

When you think of a rice casserole the image of rice mixed together with a concoction of canned cream soups comes to mind, but with this Cheesy Mushroom Rice Casserole, there are no canned ingredients in sight! A from-scratch cheese sauce might sound daunting, but it is so easy to whip up!
The sauce’s base is onions sautéed until tender. Then the mushrooms get added and cooked until they get some color on the exterior. You can choose any sort of mushroom you have available at your store, just make sure they are cleaned of any residual dirt and chopped into small pieces.

Once the mushrooms start to get some color on them, add in the remaining butter and cook until the butter melts. Whisk the flour in, creating the roux for the cream sauce. When the roux forms into a paste, gradually add the milk, a little bit at a time.

As the last bit of milk is poured into the sauce, add in the seasonings. A bit of sage, thyme, and nutmeg amplify the earthiness of the mushrooms and give that taste of the holidays to the dish!

Mix in the rice and cheese.

Transfer to the prepared baking dish and top with the remaining cheese and bake!


The casserole is done when the sides are bubbly and the top is golden!


A bite of this Cheesy Mushroom Rice Casserole is a perfect way to welcome the cooler weather.


The comfort of simple white rice gets a decadent overhaul with a cheesy and creamy sauce. Herbs, sautéed onions, and mushrooms add something special and a bit of complexity to a classic casserole dish.
Cheesy Mushroom Rice Casserole
Yield(s): Serves about 6
20m prep time
30m cook time
Diet: Vegetarian
Ingredients
- 6 tablespoons unsalted butter, divided
- 1 small onion, finely chopped
- 8 to 10 ounces mushrooms, cleaned and roughly chopped (cremini, baby bellas, porcini, and maitake work well)
- 3 tablespoons all-purpose flour
- 2 3/4 cups whole milk, room temperature
- 1 teaspoon dried thyme
- 3/4 teaspoon ground nutmeg
- 1/2 teaspoon dried sage
- 4 cups cooked white rice
- 1 3/4 cups grated white cheddar cheese, divided
- Kosher salt and freshly cracked black pepper, to taste
Preparation
- Preheat oven to 350°F and grease a 9x9 casserole dish with baking spray, set the casserole dish on top of a foil-lined baking sheet, and set aside.
- In a medium saucepan set over medium heat, melt 3 tablespoons butter and saute onions until soft and slightly translucent, about 8 to 10 minutes.
- Add mushrooms, cooking until they get some golden color on them, about 4 to 5 minutes.
- Add remaining 3 tablespoons butter to the pot. Once melted, whisk in flour, creating a base for a roux.
- Gradually add in milk, 1/2 cupful at a time, whisking constantly to prevent lumps. Once the sauce begins to thicken, add the next portion of milk.
- Once all of the milk is added, bring the sauce to a simmer and whisk in thyme, nutmeg, and sage. Season with salt and pepper.
- Turn the heat off and pour in the rice and 1 cup cheese, mixing to combine.
- Pour the mixture into the prepared pan and top with remaining 3/4 cup cheese.
- Bake until the sides start to bubble and the top is golden, about 25 to 30 minutes. Serve warm and enjoy!
Recipe adapted from Sarcastic Cooking and Rachael Hartley Nutrition.











