Mushroom and Wild Rice Casserole
Mushroom and wild rice casserole turns simple pantry ingredients into a creamy, savory dinner with tender rice, golden mushrooms, and a bubbling Gruyère top.
This casserole feels rich and cozy, but it still uses real, simple ingredients. Wild rice brings a nutty flavor and a chewy texture. Mushrooms add deep umami. Celery, onion, garlic, and thyme make the whole kitchen smell like a slow-cooked meal, even though the prep stays easy.
Why You Will Love This Recipe
- Big savory flavor: Browned mushrooms, garlic, thyme, and Gruyère make every bite taste deep and comforting.
- Creamy but not heavy: A modest amount of cream coats the wild rice without drowning it.
- Great texture: Wild rice stays pleasantly chewy while the cheese melts into a bubbly top.
- Easy to prep ahead: Cook the rice earlier in the day, then assemble and bake when you are ready.
Fabian’s Budget & Health Tip: Use half cremini mushrooms and half basic white button mushrooms if prices are high. You still get rich mushroom flavor, especially when you brown them well. Wild rice adds fiber, minerals, and a nutty whole grain bite, so the casserole feels filling without needing a large amount of cheese or cream.
Ingredients (Serves 4)
- 1 cup uncooked wild rice (160 g), rinsed
- 3 cups vegetable broth (720 ml)
- 2 tablespoons olive oil (30 ml)
- 16 ounces mushrooms (450 g), sliced, such as cremini or button mushrooms
- 2 celery ribs (100 g), finely chopped
- 1 medium yellow onion (150 g), finely chopped
- 3 garlic cloves (9 g), minced
- 1 teaspoon dried thyme (1 g), or 1 tablespoon fresh thyme leaves (3 g)
- 3 quarter cup heavy cream (180 ml)
- 1 cup grated Gruyère cheese (110 g), divided
- 1 teaspoon kosher salt (6 g), plus more to taste
- 1 half teaspoon black pepper (1 g)
Step-by-Step Instructions
1. Cook the Wild Rice
Add the rinsed wild rice and vegetable broth to a medium pot. Bring it to a boil, then lower the heat and cover the pot. Simmer for 40 to 50 minutes, until the grains split open and taste tender with a gentle chew.
If extra broth remains, drain it well. Fluff the rice with a fork and set it aside. The rice should smell nutty and earthy.
2. Heat the Oven and Prepare the Baking Dish
Heat the oven to 375 degrees F (190 degrees C). Lightly grease a medium baking dish with a small splash of olive oil. Use a dish that holds about 2 quarts so the casserole bakes evenly and bubbles at the edges.
3. Brown the Mushrooms
Heat the olive oil in a large skillet over medium-high heat. Add the sliced mushrooms in an even layer. Let them cook without stirring for 3 to 4 minutes so they can brown instead of steam.
Stir and keep cooking until the mushrooms shrink, release their moisture, and turn golden at the edges. This step builds the deep savory base of the casserole.
4. Sauté the Celery, Onion, Garlic, and Thyme
Add the celery and onion to the skillet with the mushrooms. Cook for 5 to 6 minutes, stirring often, until the onion looks soft and glossy and the celery loses its raw crunch.
Add the garlic, thyme, salt, and black pepper. Stir for about 1 minute, just until the garlic smells warm and fragrant. Do not let it burn, since burnt garlic tastes sharp.
5. Mix the Casserole Filling
Add the cooked wild rice to the skillet. Pour in the cream and add half of the Gruyère cheese. Stir until the rice looks creamy and the cheese starts to melt into the mushrooms.
Taste the mixture. Add a small pinch of salt if the flavors taste flat. The filling should taste savory, earthy, and lightly creamy before it goes into the oven.
6. Top and Bake Until Bubbling
Spoon the mixture into the prepared baking dish. Sprinkle the remaining Gruyère over the top in an even layer.
Bake for 20 to 25 minutes, until the edges bubble and the cheese melts into a golden, lightly crisp top. Let the casserole rest for 5 minutes before serving so the cream settles into the rice.
Expert Troubleshooting & FAQs
Why is my wild rice still firm?
Wild rice takes longer than white rice. Keep simmering it until the grains split and the center feels tender. If the pot dries out before the rice softens, add a splash of water or broth and keep cooking.
Why did my casserole turn watery?
The mushrooms may not have cooked long enough. Let them release their liquid, then keep cooking until that liquid evaporates and the mushrooms brown. Also drain any extra broth from the wild rice before mixing.
Can I make this mushroom and wild rice casserole ahead of time?
Yes. Cook the rice and mushroom mixture, then combine everything in the baking dish. Cover and chill for up to 24 hours. Bake it straight from the fridge, adding 5 to 10 extra minutes as needed.
Can I use a different cheese instead of Gruyère?
Yes. Swiss cheese works well and usually costs less. Sharp white cheddar also tastes good, but it gives the casserole a stronger, less nutty flavor.
Can I make it lighter?
You can replace half of the cream with extra vegetable broth. The casserole will taste less rich, but the wild rice, mushrooms, garlic, and thyme still give it plenty of flavor.
Estimated Nutritional Facts
Rough estimate per serving:
- Calories: 430
- Protein: 14 g
- Carbs: 48 g
- Fats: 21 g
Mushroom and Wild Rice Casserole
Ingredients
- 1 cup uncooked wild rice (160 g), rinsed
- 3 cups vegetable broth (720 ml)
- 2 tablespoons olive oil (30 ml)
- 16 ounces mushrooms (450 g), sliced, such as cremini or button mushrooms
- 2 celery ribs (100 g), finely chopped
- 1 medium yellow onion (150 g), finely chopped
- 3 garlic cloves (9 g), minced
- 1 teaspoon dried thyme (1 g), or 1 tablespoon fresh thyme leaves (3 g)
- 3 quarter cup heavy cream (180 ml)
- 1 cup grated Gruyère cheese (110 g), divided
- 1 teaspoon kosher salt (6 g), plus more to taste
- 1 half teaspoon black pepper (1 g)
Instructions
- 1. Cook the Wild Rice. Add the rinsed wild rice and vegetable broth to a medium pot. Bring it to a boil, then lower the heat and cover the pot. Simmer for 40 to 50 minutes, until the grains split open and taste tender with a gentle chew. If extra broth remains, drain it well. Fluff the rice with a fork and set it aside. The rice should smell nutty and earthy.
- 2. Heat the Oven and Prepare the Baking Dish. Heat the oven to 375 degrees F (190 degrees C). Lightly grease a medium baking dish with a small splash of olive oil. Use a dish that holds about 2 quarts so the casserole bakes evenly and bubbles at the edges.
- 3. Brown the Mushrooms. Heat the olive oil in a large skillet over medium-high heat. Add the sliced mushrooms in an even layer. Let them cook without stirring for 3 to 4 minutes so they can brown instead of steam. Stir and keep cooking until the mushrooms shrink, release their moisture, and turn golden at the edges. This step builds the deep savory base of the casserole.
- 4. Sauté the Celery, Onion, Garlic, and Thyme. Add the celery and onion to the skillet with the mushrooms. Cook for 5 to 6 minutes, stirring often, until the onion looks soft and glossy and the celery loses its raw crunch. Add the garlic, thyme, salt, and black pepper. Stir for about 1 minute, just until the garlic smells warm and fragrant. Do not let it burn, since burnt garlic tastes sharp.
- 5. Mix the Casserole Filling. Add the cooked wild rice to the skillet. Pour in the cream and add half of the Gruyère cheese. Stir until the rice looks creamy and the cheese starts to melt into the mushrooms. Taste the mixture. Add a small pinch of salt if the flavors taste flat. The filling should taste savory, earthy, and lightly creamy before it goes into the oven.
- 6. Top and Bake Until Bubbling. Spoon the mixture into the prepared baking dish. Sprinkle the remaining Gruyère over the top in an even layer. Bake for 20 to 25 minutes, until the edges bubble and the cheese melts into a golden, lightly crisp top. Let the casserole rest for 5 minutes before serving so the cream settles into the rice.
