Stuffed Mushroom Casserole

You know that moment at the holiday table when someone asks who made the stuffed mushrooms, but no one actually spent an hour filling individual caps? That is this casserole.

White button mushrooms sautéed until tender, folded into a garlicky cream cheese sauce with mozzarella and Parmesan, then baked in a cast iron skillet until the panko topping turns golden and crunchy. All the flavor of stuffed mushrooms made in one pan, no stuffing required.

It is vegetarian, easy to prep the day before, and goes with almost any main dish. This has quietly become one of the most-requested dishes I bring to a holiday table.

Ingredients

• 1½ lbs white button mushrooms, quartered
• 3 tbsp canola oil (or olive oil)
• 1 tbsp minced garlic
• 4 oz cream cheese, softened
• ½ cup shredded mozzarella cheese
• ¼ cup grated Parmesan cheese
• ½ cup panko breadcrumbs
• Salt and black pepper to taste

For the panko topping:

• ½ cup panko breadcrumbs
• ¼ cup grated Parmesan cheese
• ¼ cup fresh parsley leaves
• 2 tbsp melted butter

How to Make Baked Mushroom Casserole

1. Preheat oven to 350°F.
2. Add oil and quartered mushrooms to a large cast iron skillet. Season with salt and pepper. Cook over medium-high heat, stirring occasionally, until mushrooms are soft and most of the liquid has evaporated — about 8 minutes. Do not rush this step.
3. Add minced garlic and softened cream cheese. Stir and cook until the cream cheese melts and fully coats the mushrooms.
4. Remove from heat. Stir in ½ cup panko, mozzarella, and ¼ cup Parmesan. Mix well.
5. In a small bowl, combine the remaining ½ cup panko, ¼ cup Parmesan, parsley, and melted butter. Stir to combine.
6. Spoon the panko topping evenly over the mushroom mixture.
7. Bake 25–30 minutes until the topping is golden brown and the casserole is bubbling at the edges. Serve immediately.

Tips for the Best Mushroom Casserole

Cook off the moisture: Mushrooms release a lot of water. Let them cook until that liquid fully evaporates before adding the cream cheese — this is what keeps the casserole creamy instead of watery.

Soften the cream cheese first: Cold cream cheese won’t melt smoothly. Leave it on the counter for 20–30 minutes before you start, or microwave for 15 seconds.

Cast iron is your best friend: It goes from stovetop to oven with no fuss and gives the topping even browning. No cast iron? Transfer to a buttered casserole dish before baking.

Garlic is personal: Add as much as you love. If you want even deeper flavor, try stirring in a spoonful of roasted garlic along with the minced.

Can You Make Mushroom Casserole Ahead of Time?

Yes — and this is the most common question I get about this recipe, especially around Thanksgiving when oven space is precious.

Complete the recipe through Step 4 (mushrooms mixed with cheese and panko). Transfer to your baking dish, cover tightly with plastic wrap, and refrigerate up to 24 hours. Do not add the panko topping yet.

When ready to bake, pull it from the fridge 20–30 minutes before going in the oven. Add the fresh panko topping, then bake as directed. The topping stays crispy and the flavor is just as good.

What to Serve With this Casserole

This casserole works as a holiday side or a simple weeknight vegetable dish. A few ways to use it:

• As a holiday side alongside broccoli cheese casserole, green bean casserole, and sweet corn casserole
• Spooned over wild rice or white rice for a heartier serving
• As a topping for simple baked chicken breasts, it is incredible this way
• With crusty bread as a warm appetizer dip, especially good for parties

Variations and Add-Ins

• Sausage — Brown ½ lb of Italian sausage or breakfast sausage and stir it in with the cheeses. Turns this into a full meal.
• Chicken — Add 1 cup of shredded rotisserie chicken with the cheeses for a heartier dish.
• Bacon — Stir in cooked crumbled bacon, or try the Tuscan butter mushrooms version for a different flavor direction.
• Onions — Sauté diced white onion with the mushrooms for extra depth.
• Fresh thyme — A few sprigs baked in add a herby, savory note that is especially good at the holidays.
• Different mushrooms — Cremini (baby bella) mushrooms have a deeper, earthier flavor and work just as well. For a quick stovetop alternative, try sautéed mushrooms and onions instead.

Frequently Asked Questions

Why is my mushroom casserole watery?

Almost always because the mushrooms were not cooked long enough before adding the cream cheese. Cook them over medium-high heat until all the released liquid has evaporated and the pan looks mostly dry. Do not skip this step.

What mushrooms work best?

White button mushrooms are the most accessible and work perfectly. Cremini or baby bella mushrooms add a slightly deeper flavor. A mix of both is great. Avoid frozen mushrooms — they make the casserole watery.

Can I make this without cream cheese?

Cream cheese is what creates the creamy, rich texture. If you need a substitute, mascarpone is the closest. Sour cream works in a pinch but will produce a thinner sauce and slightly tangy flavor.

How do I store leftovers?

Store in an airtight container in the refrigerator for up to 3 days. Reheat in a 350°F oven covered with foil to preserve the topping. A microwave works, but the topping will soften.

Can I freeze it?

Freezing is not recommended. Cream cheese and mushrooms both change texture after freezing and thawing. Make it fresh or prep-ahead refrigerated for up to 24 hours instead.

More Mushroom Recipes to Try

• Whole Roasted Garlic Mushrooms — Sheet pan, 15 minutes, impressive with minimal effort.
• Cream Cheese Stuffed Portobello Mushrooms — Keto-friendly, filling enough to serve as a main.
• Garlic Cauliflower and Mushrooms — Quick 20-minute skillet side that pairs with anything.
• Crockpot Ranch Mushrooms — Buttery, tender, and completely hands-off in the slow cooker.