Vegetarian Rice Casserole is an elegant, make-ahead casserole with brown rice, mushrooms, carrot, green onion, parmesan cheese, and a touch of white wine. This creamy brown rice casserole recipe is perfect for a potluck or special occasion dinner, makes a substantial amount, and has phenomenally delicious flavor to complement any meal.
This glorious recipe for this fancy impressive vegetarian rice casserole takes me back! I do not remember where I got the recipe originally, but I do know that this was one of the first I ever made when I learned how to cook.
So, that said, the directions may sound like there is a lot of business entailed here, but there really is not. If I could knock this out as a novice (which I totally did), you can too.
Why this recipe works
This brown rice casserole recipe works because it is elegantly simple, but SO delicious with the combination of flavors. Beautiful browned mushrooms, nutty flavorful brown rice, lots of green onion, parsley, and parmesan cheese, and a hint of white wine – this side dish is DELICIOUS.
At the same time, this collection of flavors complement not only each other, but also whatever you pair this side dish with. I have made it to go with Swiss chicken, steak on Valentine’s Day, and prime rib on Christmas.
I have also made it on its own to serve with other vegetarian dishes to make all together a complete meal (sans meat). Nommm.
This recipe also works because all the work is done a day in advance. All of the ingredients are cooked, the casserole is assembled in layers, then a mixture of egg and half-and-half is poured over all.
Once the vegetarian rice casserole sits overnight to let the flavors blend and creamy egg mixture penetrate every nook and cranny, we bake. Low stress when we need it, perfect for making and sharing with others.
Ingredients for Vegetarian Rice Casserole
This dish is assembled in layers, so I will give you the ingredients organized by layers for simplicity sake.
Ingredients for the brown rice layer
- Extra virgin olive oil.
- Carrot. Two regular carrots, diced small. This ends up at around a cup of carrot.
- Uncooked brown rice.
- Vegetable stock. Vegetable stock is preferable to vegetable broth since it has more flavor, but either can be used.
- Dry white wine. Chardonnay, Pino Grigio, or Sauvignon Blanc all work.
- Seasonings: kosher salt and fresh cracked pepper.
Ingredients for the mushroom layer
- Extra virgin olive oil.
- Fresh mushrooms. I get mushrooms that are pre-sliced to make preparation easier.
- Green onions. We use the light green and white parts of one whole bunch.
- Fresh parsley. Use flat-leaf (aka Italian) parsley.
- Freshly grated parmesan cheese. You can buy parmesan already grated, but be sure to get fresh parmesan in the dairy section. You do not want pantry section parmesan.
More vegetarian casserole recipes
How to make brown rice casserole
As with the ingredients above, directions for this vegetarian rice casserole are best understood are best understood in terms of layers, so I will break up the steps that way.
Prepare the brown rice
First, we sauté the carrot for a couple minutes in olive oil. Add the rice and cook another minute. This serves to toast the grains of rice and increase flavor.
Add the vegetable stock, bring to a simmer, cover, reduce heat to low, and cook until rice is done. This is standard practice to cook brown rice.
Once the rice is cooked tender, we stir in the salt, pepper, and parsley. I specify 1-½ teaspoons salt in the recipe card, but I highly recommend tasting for seasoning, and I usually do end up adding another couple pinches.
Brown the mushrooms
While the rice is cooking, we prepare the mushrooms by browning them in olive oil. For more detailed instruction on specifically how to brown mushrooms, visit here.
Once the mushrooms are browned, we add the green onion and garlic and give it another minute to soften the onion and get the garlic fragrant. Set this aside.
Assemble the rice casserole
This casserole is assembled in a 13×9 bake dish in easy layers as follows: half the rice, all the mushrooms-green onion mixture, half the parmesan cheese, the rest of the rice, and the rest of the parmesan cheese.
Then, we combine the eggs, half-and-half, and touch of nutmeg – whisk that until smooth – then pour this “custard” mixture over all the casserole.
Cover and refrigerate overnight. I use plastic wrap to tightly cover the bake dish.
Cook, serve, and enjoy
The next day, we get our vegetarian rice casserole out and let it sit a bit on the counter to get the chill off. I say 20 minutes in the instruction, but this can be longer.
Then we just pop it in the oven and bake until nicely heated through. Easy peasy.
Tips and FAQs
Using a heavy-bottomed (meaning, thicker) pot is preferable to help prevent the rice from burning to the bottom as it cooks (which has happened to me more times than I want to dmit using thinner cheaper pots).
I am a heavy salter, so I left the amount of salt on the conservative side in the recipe card because you can always add more (like me) but you cannot take it out once added if it is too much for your taste. So, be sure to taste for seasoning and add more incrementally if you like.
Can this vegetarian rice casserole be cooked in advance? Ehh, I don’t recommend it. Even keeping it covered tightly with foil, the rice around the edges will dry out. The cook time is so short, it is better to cook the day of serving.
Can white rice be substituted for brown rice? Yes, simply adjust the cook time and amount of vegetable stock to fit the corresponding package directions.
Does this casserole freeze well? Not really. Rice does not do well freezing then thawing as it has a tendency to dry out and get too firm.
Vegetarian Rice Casserole
- 5 Tbsp extra virgin olive oil divided
- 1 cup diced carrots (~2 medium) small dice
- 2 cups uncooked brown rice
- 4 ½ cups vegetable stock
- ½ cup dry white wine
- 1 ½ tsp kosher salt
- ¼ tsp fresh cracked pepper
- ½ cup chopped fresh parsley
- 1 (8 oz) pkg fresh mushrooms sliced
- 1 bunch green onions (white and light green parts only) chopped
- 2 cloves garlic minced
- 1 cup freshly grated parmesan cheese
- 2 large eggs lightly beaten
- 1 cup half-and-half
- ⅛ tsp ground nutmeg
Cook the brown rice
- Heat 2 tablespoons olive oil in a heavy-bottomed pot. Add the carrot and sauté 3 minutes until carrot is just golden. Add the rice and cook 1 minute.
- Add the stock and wine to the rice and bring to a boil. Cover, reduce heat to low, and simmer 45 minutes or until the liquid is absorbed and rice is tender.
- Remove from the heat and add the salt, pepper, and parsley. Taste for seasoning, especially salt, and add more if desired.
Brown the mushrooms
- While the rice is cooking, heat the remaining 3 tablespoons olive oil in a skillet over high heat. Add the mushrooms and sauté until nicely browned.
- Add the green onion and garlic, and cook 1 minute until onion is softened and garlic is fragrant. Remove from the heat. Season with a pinch each kosher salt and cracked pepper.
Assemble the casserole
- Layer half of rice mixture in a greased 13×9 baking dish. Spoon mushroom-onion mixture over the rice, and top with ½ cup parmesan. Spread the remaining rice on top and top with the remaining ½ cup parmesan.
- In a bowl, whisk together the eggs, half-and-half, and nutmeg. Pour over the casserole. Cover and refrigerate 8-24 hours.
Cook the casserole
- Remove the casserole from the refrigerator and let stand 20 minutes to come to room temperature.
- Heat oven to 350°F. Bake the casserole uncovered at 350°F for 20 minutes or until heated through.
Calorie count is purely an estimate calculated using an online application to serve as a guide and not to be taken as accurate nutritional information. Percent Daily Values are based on a 2,000 calorie diet.