There’s something so satisfying about a bubbling, golden-brown casserole that brings everyone to the table, and Mushroom Polenta Casserole is truly one of those magical dishes. Layers of creamy, cheesy polenta and hearty, umami-packed mushrooms come together in a cozy bake that’s as easy to whip up on a weeknight as it is impressive for a dinner party. Whether you’re looking for a vegetarian centerpiece or a comforting side, every bite of this Mushroom Polenta Casserole delivers incredible flavor and rustic charm.

Ingredients You’ll Need

Mushroom Polenta Casserole Recipe - Recipe Image

Ingredients You’ll Need

The magic of Mushroom Polenta Casserole comes from simple, wholesome ingredients, each contributing its unique flair, from creamy texture to earthy flavor and vibrant color. Don’t skip any – they work in perfect harmony for a truly memorable dish.

Polenta: The heart of the casserole, polenta gives that luscious, creamy base and holds everything together beautifully.
Mixed mushrooms: Go wild with creminis, shiitakes, or portobellos for the deepest, most satisfying savory notes.
Olive oil: Just a splash brings out the natural flavors of the mushrooms and keeps everything velvety soft.
Garlic: A few cloves make all the difference, infusing every bite with rich, aromatic depth.
Shallots or onions: These add gentle sweetness and complexity to the mushroom filling.
Vegetable broth: Choose a good-quality broth, since it enhances the savory undertones of both the polenta and the mushrooms.
Fresh herbs (like thyme or parsley): These brighten up the casserole with fresh, fragrant flavor right at the end.
Parmesan cheese (or a plant-based alternative): Melty cheese adds a salty, nutty kick and a gorgeous golden crust.
Salt and pepper: A generous season keeps all the flavors perfectly balanced and vibrant.
Butter (or vegan butter): Just a pat gives the polenta extra richness and smoothness.

How to Make Mushroom Polenta Casserole

Step 1: Prep the Mushrooms

Start by cleaning and slicing your mushrooms. Heat olive oil in a large skillet over medium-high heat, then add the mushrooms with a pinch of salt. Sauté until their liquid has evaporated and they’re beautifully browned. Add chopped garlic and shallots, cooking for a minute or two until fragrant. This layer builds deep, savory flavor at the heart of your Mushroom Polenta Casserole.

Step 2: Cook the Polenta

Bring your vegetable broth to a gentle simmer in a saucepan, then slowly whisk in the polenta. Keep stirring to prevent lumps, and cook until the mixture is thick, creamy, and glossy. Off the heat, stir in butter, most of the Parmesan, and a generous pinch of salt and pepper. This plush layer will cradle your mushroom filling perfectly.

Step 3: Layer the Casserole

Spoon half of the creamy polenta into a greased baking dish and spread it out. Layer over your sautéed mushrooms and sprinkle with a bit of fresh herbs. Add the remaining polenta on top, smoothing it into an even layer. For a glorious finish, dust the last of the Parmesan over everything.

Step 4: Bake until Golden

Slide your assembled casserole into a hot oven and bake until the top is gently golden and crisp, and the whole dish is bubbling around the edges. This step brings all the components together and ensures that gorgeous, irresistible crust that everyone’s eager to scoop into.

Step 5: Finish with Fresh Herbs

Once the Mushroom Polenta Casserole is baked, let it rest for a few minutes. Scatter on more fresh herbs for vivid color and extra burst of freshness, then serve hot and enjoy those swoon-worthy layers in every forkful.

How to Serve Mushroom Polenta Casserole

Garnishes

Top your Mushroom Polenta Casserole with a shower of finely chopped fresh parsley or thyme, a drizzle of good olive oil, and an extra scattering of Parmesan if you like. The herbs add brightness, and a little finishing cheese makes it feel even more luxurious.

Side Dishes

This casserole shines alongside a crisp green salad dressed simply with lemon and olive oil, or you can pair it with roasted vegetables for an even heartier meal. Crusty bread on the side turns it into a feast worthy of any gathering.

Creative Ways to Present

For a stunning dinner party presentation, bake your Mushroom Polenta Casserole in individual ramekins or mini cocottes. It’s also beautiful served family-style, with a big spoon so everyone can admire those creamy layers. A sprinkle of microgreens or edible flowers makes it extra special.

Make Ahead and Storage

Storing Leftovers

If you have leftovers, transfer the casserole to an airtight container and refrigerate. The flavors deepen overnight, making it a delicious lunch or supper the next day. It keeps well for up to 3 days in the fridge.

Freezing

This Mushroom Polenta Casserole freezes surprisingly well! Cut it into portions, wrap tightly with foil or plastic wrap, and store in a freezer-safe container. It’ll keep for up to one month; just thaw overnight in the refrigerator before reheating.

Reheating

To reheat, cover the casserole with foil and bake in a low oven until warmed through. If you’re heating just a single portion, a quick spin in the microwave works perfectly. Add a sprinkle of fresh herbs or cheese before serving to refresh the flavors.

FAQs

Can I use instant polenta instead of regular?

Absolutely! Instant polenta speeds things up considerably. Just keep an eye on cooking times and texture, as instant varieties set up more quickly.

What mushrooms work best in Mushroom Polenta Casserole?

A mix of cremini, shiitake, and portobello mushrooms delivers incredible depth, but even just one variety will give you beautiful results. Use whatever’s freshest or available to you.

How can I make it vegan?

Swap out the Parmesan for a plant-based alternative and use vegan butter. With flavorful broth and mushrooms, this dish is naturally rich, so you won’t miss the dairy at all.

Do I need to bake the casserole, or can I eat it as a skillet meal?

While baking gives Mushroom Polenta Casserole its gorgeous crust, you can absolutely enjoy it straight from the stove for a cozy, creamy skillet dinner—just skip the final baking step.

Can I add vegetables or protein?

Definitely! Spinach, kale, or roasted red peppers make a lovely addition. For more protein, try stirring in cooked lentils or topping with crispy chickpeas for extra texture and nutrition.

Final Thoughts

If you’re looking for a dish that brings warmth, comfort, and a bit of rustic elegance to your table, Mushroom Polenta Casserole ticks all the boxes. It’s simple to make, endlessly adaptable, and guaranteed to become a new favorite in your kitchen. Give it a try and watch friends and family go back for seconds!