Creamy Mushroom Wild Rice Casserole

The first time I made this casserole was during a particularly brutal November when the wind rattled my windows and I needed something that felt like a warm blanket in food form. I'd been eyeing wild rice at the grocery store for weeks, those dark slender grains promising something more substantial than the usual white rice rotation. My kitchen smelled incredible as the mushrooms hit hot butter and sage filled the air.

I brought this to a friendsgiving last year and watched my friend Sarah literally scrape her plate clean before going back for seconds. She's not usually one to get excited about vegetarian mains, but something about the earthy mushrooms and that rich, velvety sauce won her over completely. Now she requests it every time we plan a potluck dinner.

Ingredients

• 1 cup uncooked wild rice blend: The nutty flavor and chewy texture here is non-negotiable, regular rice just won't give you that same satisfying bite
• 2 cups vegetable broth: Use a good quality broth because it's going to reduce down and concentrate as the rice cooks
• 1 cup water: Wild rice can be thirsty and you want to make sure it has enough liquid to become perfectly tender
• 2 tablespoons unsalted butter: This creates that rich foundation for sautéing all your vegetables
• 1 tablespoon olive oil: Combined with butter, it prevents burning while still giving you that beautiful buttery flavor
• 1 large yellow onion, finely chopped: The sweetness that develops as it cooks balances all those earthy mushrooms
• 3 garlic cloves, minced: Don't be shy here, garlic blooms beautifully in this creamy sauce
• 1 pound cremini mushrooms, sliced: These little guys have so much more flavor than plain white buttons and they hold their texture better
• 2 celery stalks, diced: This adds this subtle aromatic backbone that people can never quite put their finger on
• 2 medium carrots, diced: They bring this natural sweetness and pops of color throughout the dish
• 1/2 cup frozen peas: Tossed in at the end, they stay bright and sweet, no mushy peas here
• 1/4 cup all-purpose flour: This is what transforms your milk into that silky thick sauce that binds everything together
• 2 cups whole milk: Whole milk gives you that luxurious creaminess, though I've made it successfully with unsweetened almond milk too
• 1/2 cup sour cream: This is the secret to that tangy, restaurant-quality finish that makes people ask what's in it
• 1/2 cup grated Parmesan cheese: Salty and nutty, it deepens all the other flavors without overpowering
• 1/2 teaspoon dried thyme: Earthy and woodsy, it's practically made for mushrooms
• 1/2 teaspoon dried sage: This is what makes it taste like comfort food, like hugs in herb form
• 1/2 teaspoon salt: Start here, you can always add more at the end
• 1/4 teaspoon black pepper: Freshly ground makes a huge difference here
• 1/2 cup panko breadcrumbs: They create this lighter, crunchier topping than traditional breadcrumbs
• 2 tablespoons melted butter: Tossed with the panko, this is what transforms them into golden perfection
• 1/4 cup grated Parmesan cheese: Extra cheese on top because why not, it gets crispy and salty in the oven

Instructions

Get that rice going first:

Preheat your oven to 375°F and grab a 9x13 baking dish, giving it a quick butter massage so nothing sticks later. In a medium saucepan, combine your wild rice, broth, and water, then bring it to a boil before dropping the heat to low, covering, and letting it simmer for about 40 to 45 minutes until those grains are tender and have drank up all the liquid.

Build your flavor foundation:

While the rice works, melt your butter with that splash of olive oil in a large skillet over medium heat. Toss in your onion, garlic, mushrooms, celery, and carrots, then let them hang out for 8 to 10 minutes, stirring occasionally, until everything's softened and those mushrooms have released all their liquid into the pan.

Create that creamy magic:

Sprinkle your flour over the vegetables and stir it around for about a minute so it loses that raw taste. Slowly pour in your milk, stirring constantly as you go, and keep at it for 3 to 4 minutes until you've got this gorgeous thick sauce coating everything.

Bring it all together:

Pull the pan off the heat and stir in your sour cream, Parmesan, thyme, sage, salt, and pepper. Fold in your cooked wild rice and those frozen peas, then tumble the whole thing into your prepared baking dish, using a spoon to smooth the top into an even layer.

Make that golden topping:

In a small bowl, toss together your panko, melted butter, and extra Parmesan until the breadcrumbs are evenly coated. Sprinkle this mixture all over the top of your casserole like you're tucking it in for a cozy nap.

Bake until bubbly and golden:

Slide it into the oven and let it bake uncovered for 25 to 30 minutes until that topping is deeply golden and you can see the sauce bubbling up around the edges. Give it 10 minutes to rest before serving, which feels impossible but helps everything set so each scoop holds together beautifully.

Save

My mom called me mid-bake once while I was making this, asking what I was up to, and when I described the dish she stayed on the phone with me through the entire topping assembly process. She said she could practically smell it through the phone and now she makes it for her book club, claiming she adapted the recipe from her talented daughter.

Make It Your Own

I've discovered that swapping half the wild rice for brown rice adds this wonderful nutty depth, though you'll need to adjust the cooking time since brown rice takes longer. Sometimes I'll throw in a handful of chopped fresh spinach right at the end just to sneak in some greens, and nobody's ever complained about extra vegetables.

The Make-Ahead Magic

This might be the ultimate make-ahead dish, which I learned the hard way when I accidentally assembled it the night before a dinner party and then panicked that I'd ruined everything. It actually baked up better than fresh, the flavors having had all night to become best friends with each other, and now I never make it same-day anymore.

Serving Suggestions

A simple green salad with a bright vinaigrette cuts through all that richness and makes this feel like a complete meal. On colder nights, I'll serve it alongside some roasted Brussels sprouts or steamed broccoli, anything fresh and green to balance all that creamy comfort.

• Cranberry juice or a crisp white wine pairs surprisingly well with the earthy mushrooms
• Crusty bread is never a bad idea, even though you definitely don't need it
• A light dessert like poached pears or sorbet keeps the meal from feeling too heavy

Save

There's something deeply satisfying about serving a dish that looks impressive but comes together with such humble ingredients. Every time I pull this bubbling, golden beauty out of the oven, I'm reminded that sometimes the most comforting foods are also the simplest.

Recipe Questions & Answers

→ Can I make this casserole ahead of time?

Assemble the entire casserole up to 24 hours in advance, cover tightly, and refrigerate. Add 10-15 minutes to baking time if baking cold from the refrigerator. Alternatively, bake completely and reheat individual portions.

→ What type of wild rice works best?

A wild rice blend that combines true wild rice with brown rice offers excellent texture and flavor. Pure wild rice has a stronger flavor and longer cooking time, so adjust liquid and timing accordingly if using 100% wild rice.

→ Can I freeze this casserole?

Yes, freeze before baking for best results. Wrap the assembled dish tightly in plastic and foil for up to 3 months. Thaw overnight in the refrigerator before baking, or bake frozen at 350°F for about 60-75 minutes.

→ What mushrooms should I use?

Cremini mushrooms provide excellent flavor and texture, but button mushrooms work well too. For more depth, try combining cremini with shiitake or portobello mushrooms. Fresh mushrooms yield the best results.

→ How can I make this gluten-free?

Substitute all-purpose flour with a 1:1 gluten-free flour blend containing xanthan gum, and use certified gluten-free panko breadcrumbs. The rest of the ingredients are naturally gluten-free.

→ What protein can I add?

Stir in 2-3 cups of shredded rotisserie chicken, cooked turkey, or cubed tofu with the rice. For vegetarians, add protein-rich ingredients like chickpeas, white beans, or additional nuts.