
This soul-warming casserole celebrates the earthy richness of mushrooms bathed in a creamy sauce and blanketed with golden, bubbling cheese. Each spoonful delivers a perfect harmony of flavors—savory mushrooms, tangy sharp cheddar, nutty Parmesan, and aromatic herbs—creating an irresistible dish that satisfies deeply with its simple yet sophisticated taste. The contrast between the tender mushrooms and crispy, buttery breadcrumb topping offers a textural experience that elevates this casserole from merely delicious to utterly memorable.
I first served this casserole at a dinner party where one guest was vegetarian. To my surprise, it was the first dish to disappear completely, with meat-eaters going back for seconds and thirds. My brother-in-law, who typically pushes mushrooms aside on his plate, took a reluctant bite at my insistence and ended up requesting the recipe for his own family gatherings. There's something magical about the transformation mushrooms undergo when bathed in cream and topped with golden cheese that converts even the skeptics.
Ingredients
- Button mushrooms: The foundation of the dish, providing meaty texture and earthy flavor. Choose firm, unblemished mushrooms with tightly closed caps for the freshest taste.
- Heavy cream: Creates the rich, velvety sauce that envelops the mushrooms. Its high fat content prevents curdling during baking and delivers unmatched richness.
- Cheddar cheese: Adds a sharp, tangy dimension and creates that irresistible golden top. Freshly grated melts more smoothly than pre-shredded, which contains anti-caking agents.
- Parmesan cheese: Contributes a salty, nutty depth that enhances the umami quality of mushrooms. Authentic Parmigiano-Reggiano offers the most complex flavor.
- Dried thyme: Complements mushrooms with its subtle woodsy notes. Crushing the dried leaves between your fingers before adding releases more aroma.
- Garlic powder: Infuses the dish with aromatic depth without the risk of burning that comes with fresh garlic. Use fresh, aromatic powder for best results.
- Breadcrumbs: Create a satisfying crispy contrast to the creamy interior. Panko breadcrumbs offer the lightest, crispiest texture if available.

Instructions
- Prepare the mushrooms properly:
- Begin by cleaning 1 pound of button mushrooms with a damp paper towel rather than washing them under running water. Mushrooms act like sponges and can become waterlogged, which prevents proper browning and dilutes their flavor. Once cleaned, slice the mushrooms into even pieces, about ¼-inch thick. Uniformity ensures they'll cook at the same rate, while the thickness allows them to maintain their texture during baking rather than shrinking into nothingness. In a large bowl, toss the sliced mushrooms with 1 tablespoon of olive oil until evenly coated. The thin coating of oil helps the seasonings adhere and promotes even browning.
- Season with precision:
- To the oiled mushrooms, add 1 teaspoon of garlic powder, 1 teaspoon of dried thyme, ½ teaspoon of salt, and ¼ teaspoon of freshly ground black pepper. Toss thoroughly to ensure each mushroom slice is seasoned. This direct seasoning of the mushrooms, rather than just adding flavors to the cream, ensures that the mushrooms themselves carry flavor, creating a more complex taste experience. The thyme and garlic specifically complement the earthy quality of mushrooms, enhancing their natural flavor rather than masking it. Take a moment to ensure the seasonings are evenly distributed for consistent flavor throughout the casserole.
- Assemble with care:
- Lightly grease a 9×13 inch baking dish with butter or cooking spray to prevent sticking and ease serving. Spread the seasoned mushroom mixture evenly across the bottom of the dish, creating a uniform layer. Sprinkle 1 cup of shredded cheddar cheese and ½ cup of grated Parmesan cheese over the mushrooms, distributing it evenly to ensure every portion gets an equal amount of cheesy goodness. Pour 1 cup of heavy cream slowly and evenly over the entire dish. The cream will seep down through the layers, creating a rich sauce that binds everything together as it bakes. In a small bowl, combine 2 tablespoons of melted unsalted butter with ½ cup of breadcrumbs until every crumb is moistened. This butter coating ensures the breadcrumbs will turn golden and crispy rather than dry and powdery. Sprinkle this mixture evenly over the top of the casserole to create a delicious textural contrast.
- Bake to golden perfection:
- Place the casserole in a preheated 375°F (190°C) oven and bake for 25-30 minutes. During this time, several transformations occur: the mushrooms release their flavorful juices, which mingle with the cream to create a sauce; the cheese melts and begins to bubble around the edges; and the breadcrumb topping turns golden brown. Watch for visual cues of doneness—the edges should be bubbling vigorously, and the top should be a rich golden color. For an extra-crispy topping with maximum visual appeal, switch the oven to broil for the final 2-3 minutes, watching carefully to prevent burning. Once done, allow the casserole to rest for 5 minutes before serving. This brief resting period allows the bubbling sauce to settle and thicken slightly, making it easier to serve neat portions. Garnish with freshly chopped parsley just before bringing to the table for a pop of color and fresh flavor.
I discovered the magic of mixing mushroom varieties by accident when I was short on button mushrooms and supplemented with cremini and shiitake from my garden. The depth of flavor was noticeably enhanced, with each type contributing its own character—cremini adding meatiness and shiitake bringing a subtle smokiness. Now I deliberately use a blend whenever possible. For the best flavor development, I've found that allowing the sliced mushrooms to sit with their seasonings for 15-20 minutes before assembling gives the salt time to draw out moisture and concentrate their flavor, resulting in a more intense mushroom taste in the final dish.
Perfect Pairing Suggestions
This versatile casserole can be served in multiple ways to create a complete meal. For a simple weeknight dinner, pair it with a crisp green salad dressed with a light vinaigrette—the acidity helps cut through the richness of the cheese and cream. The contrast between the warm casserole and cool, crunchy salad creates a satisfying balance.
For a more substantial meal, serve alongside roasted chicken or grilled steak. The mushroom casserole complements these proteins beautifully, with its savory depth enhancing the meat without competing with it. A crusty baguette is essential for sopping up the remaining sauce—too delicious to leave behind.
Wine enthusiasts will appreciate how this dish pairs with medium-bodied reds like Pinot Noir or Merlot, whose earthy notes echo the mushrooms, or a buttery Chardonnay that complements the creamy sauce.

Make-Ahead and Storage Tips
One of this casserole's greatest attributes is its make-ahead potential. Prepare everything up to the point of adding the breadcrumb topping, cover tightly with plastic wrap, and refrigerate for up to 24 hours. When ready to bake, remove from the refrigerator 30 minutes before cooking to take the chill off, add the breadcrumb mixture, and proceed with baking as directed, adding about 5-7 minutes to the cooking time.
Leftovers retain their deliciousness for up to 3 days when stored in an airtight container in the refrigerator. Reheat individual portions in the microwave for 1-2 minutes or place the entire casserole, covered with foil, in a 325°F oven until heated through, about 15-20 minutes.
While the texture is best when freshly made, you can freeze the unbaked casserole for up to 3 months. Thaw completely in the refrigerator overnight before baking as directed.
After making this casserole countless times, I've learned that the quality of cheese makes a significant difference in the final result. I once used an aged, artisanal cheddar that elevated the dish from excellent to extraordinary, adding complex notes that developed beautifully during baking. For special occasions, I now splurge on high-quality cheese and can genuinely taste the difference. Another discovery was adding a pinch of nutmeg to the cream—an old chef's trick that enhances creamy sauces without being identifiable on its own. These subtle refinements transform a simple casserole into something truly special that friends and family will request again and again.
Frequently Asked Questions
- → Can I use different types of mushrooms?
- Absolutely! While button mushrooms work great, you can use cremini, portobello, shiitake, or a mix of mushrooms for more complex flavors.
- → How can I make this recipe ahead of time?
- You can prepare everything up to the baking step, cover and refrigerate for up to 24 hours. When ready to serve, bake as directed, adding an extra 5-10 minutes to the cooking time.
- → What can I serve with this mushroom casserole?
- This versatile dish pairs well with grilled meats, roasted chicken, or a simple green salad. It also makes a satisfying vegetarian main course alongside crusty bread.
- → Can I make this recipe lighter?
- Yes, you can substitute half-and-half or milk for the heavy cream, though the sauce won't be as rich. Reduced-fat cheese can also be used, but it won't melt quite as smoothly.
- → How do I know when the casserole is done?
- The casserole is ready when the edges are bubbling, the top is golden brown, and the mushrooms are tender when pierced with a fork.