Mushroom Rice Casserole
1 h
|
easy
|
Mediterranean diet,
vegetarian
Recipe by Eunice
Introduction
No bland rice on my watch: this mushroom rice casserole is garlicky, buttery, thyme-kissed, and loaded with umami from a mountain of sautéed mushrooms, so every bite hits.
It is a make-ahead, crowd-pleasing side dish built for Thanksgiving, Christmas, Mother's Day, and Easter brunch, and it slides right in beside roast turkey, glazed ham, or a simple weeknight chicken.
Ingredients (6 servings)
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Ingredients for the Rice
- 2 cups long-grain white rice (uncooked) raw long-grain white rice 11.11 oz
- 3½ cups vegetable broth vegetable broth 1.75 lb
- 1 Tbsp unsalted butter unsalted butter 0.5 oz
- 1 tsp salt salt
- ¼ tsp black pepper black peppercorns (for black pepper)
Ingredients for the Mushrooms
- 2 Tbsp olive oil olive oil
- 1 Tbsp unsalted butter unsalted butter 0.5 oz
- 3 cups mushrooms, sliced mushrooms 0.46 lb
- 1 small onion, finely chopped onion 1 ct small
- 4 cloves of fresh garlic, minced garlic 0.36 head (for fresh garlic)
- 1 tsp dried thyme dried thyme 0.02 oz
- ½ tsp salt salt
- ½ tsp black pepper black peppercorns (for black pepper)
How to Make Mushroom Rice Casserole
-
Preheat and prep the dish
Preheat the oven to 375 F and lightly grease a 9x13 inch glass or ceramic baking dish with a little olive oil.
-
Rinse and drain the rice
Rinse the long-grain white rice under cold water until the water runs almost clear to remove excess starch.
Drain very well so you do not water down the broth.
-
Sweat the onion
Heat the olive oil and 1 tablespoon butter in a large skillet over medium-high heat until shimmering.
Add the chopped onion with a small pinch of salt and cook, stirring, until translucent and slightly golden at the edges, about 3 to 4 minutes.
-
Brown the mushrooms and bloom the aromatics
Add the sliced mushrooms to the hot pan and spread them out so they have contact with the surface.
Cook undisturbed for 3 to 4 minutes, then stir and continue cooking until deeply browned and most moisture is gone, 3 to 5 minutes more.
Stir in the minced garlic and dried thyme for 30 to 60 seconds until fragrant, then season the mushrooms with 1/2 teaspoon salt and 1/2 teaspoon black pepper.
-
Assemble the casserole
Transfer the mushroom mixture to the prepared baking dish.
Add the rinsed and drained rice, pour in 3 1/2 cups vegetable broth, and sprinkle in 1 teaspoon salt and 1/4 teaspoon black pepper.
If your broth is already salty, reduce the added salt to 1/2 teaspoon and adjust later after tasting.
Dot the top with the remaining 1 tablespoon butter from the rice ingredients.
-
Bake until the rice is tender
Cover the dish tightly with foil to trap steam and bake for 35 minutes.
Remove the foil and bake 10 minutes more to let excess moisture evaporate and the top set.
-
Rest, fluff, and finish
Let the casserole rest 10 minutes off the heat so the rice finishes steaming and the grains set.
Fluff gently with a fork and finish with a few fresh grinds of black pepper before serving.
Substitutions
- Butter -> Olive oil (for a dairy-free or vegan version)
- Swap both tablespoons of butter for olive oil and you will get a cleaner, peppery finish with less richness, letting the mushrooms taste meatier while keeping the texture of the rice light.
- Button mushrooms -> Cremini, shiitake, or a mixed wild blend
- Cremini bring deeper, earthier flavor, while shiitake add a smoky, savory punch and a chewier bite that makes the casserole feel heartier without changing the technique.
- Long-grain white rice -> Long-grain brown rice
- Use the same volume of brown rice, increase broth to about 4 1/2 cups, and bake covered 55 to 60 minutes, then uncover 10 minutes, which yields a nutty taste and pleasantly chewy grains.
Tips
- Rinse like you mean it
- Washing off surface starch keeps the grains separate so you get tender rice that fluffs, not a gummy block.
- Get real color on the mushrooms
- Crowding the pan steams them, so spread them out and let them sit before stirring for deep browning and big umami.
- Taste the broth before you bake
- The liquid in the dish is your seasoning for the rice, so sip a spoonful and adjust salt and pepper now rather than after it is cooked.
- Seal the foil tight
- A snug seal traps steam, which cooks the rice evenly and prevents dry patches at the corners.
- Let it rest
- Those 10 minutes off heat allow moisture to redistribute so the grains set up fluffy and the slice holds on a plate.
- Use glass or ceramic for even results
- A glass or ceramic dish bakes more gently than thin metal, reducing hot spots and helping the bottom avoid scorching.
Nutrition Facts *
| Energy | 169 | kcal |
|---|---|---|
| Protein | 3 | g |
| Total Fat | 8 | g |
| Carbohydrates | 20 | g |
| Dietary Fiber | 2 | g |
* Approximate, per serving.
Data source: USDA FoodData Central.
FAQ
- My rice came out crunchy; what went wrong?
- The foil likely was not sealed tightly or there was not enough liquid; add 1/2 cup hot broth, re-cover, and bake 10 to 15 minutes until the grains are tender.
- The rice is mushy; how can I fix it next time?
- Too much liquid or overbaking will bloat the grains; measure the broth accurately, rinse and drain the rice well, and stick to the covered then uncovered timing without stirring mid-bake.
- Can I make this ahead?
- Yes, cool, cover, and refrigerate up to 3 days; reheat covered at 325 F with a splash of broth until hot, then uncover for 5 minutes to refresh the texture.
- Can I cook it on the stovetop instead of baking?
- Yes, combine the rice, broth, butter, salt, and pepper in a pot, bring to a simmer, add the sautéed mushroom mixture, cover, and cook on low 15 to 18 minutes, then rest 10 minutes off heat before fluffing.
- Can I use frozen mushrooms?
- Yes, cook them straight from frozen in a hot pan until they release liquid and brown, then proceed as written so the casserole does not turn watery.
- How do I add protein without drying it out?
- Fold in 1 to 2 cups cooked chickpeas or white beans after baking during the rest period, or tuck in leftover cooked chicken on top for the last 10 minutes so it warms without overcooking.
Serving Suggestions
A squeeze of lemon over each scoop and a dusting of smoked paprika wake up the mushrooms and make the whole dish pop without stealing the spotlight.
Pair it with a crunchy green salad and a garlicky yogurt or tahini sauce, or lean into cozy vibes by stirring in a spoon of sofrito before baking for deeper, savory warmth.
More pairings:
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