Unstuffed Mushroom Casserole

Deliciously rich, this casserole combines all the flavors of stuffed mushrooms with half the work! Chopped mushrooms are topped with breadcrumbs, cheese, and herbs, then baked together for a scoopable side dish or appetizer.

Stuffing mushrooms by hand is a labor of love. Each little cap has to be individually prepared, stuffed, and nestled into a dish before being baked. It brings to mind sitting around a table at holidays, working ahead in anticipation of a big holiday party with a house full of loved ones. Sometimes, though, you want to make things just a little easier, and so the idea of this casserole was born!

I’m not going to claim I’m the only person who thought of this, but when I did think of it I promise it was new to me! I wrote this recipe to be as close as possible to those individually stuffed mushrooms as possible with like 2% of the work involved.

This vegetarian, dairy-free, and egg-free dish makes a fantastic and unexpected side for steak or pasta. I love serving this as a heavy appetizer, too.

Ingredients for Unstuffed Mushroom Casserole

• Mushrooms: I used white button, but you can really use whatever type you like best.
• Cheese: sharp parmesan or asiago is best here.
• Breadcrumbs: plain, seasoned, panko, or gluten-free panko all work great in this recipe!
• Olive oil: this provides some added richness.
• Garlic powder: this adds some punch with no fuss.
• Parsley: a little bit of green goes a long way with this rich side dish.

These make a lighter, but still deliciously rich, unstuffed mushroom casserole. You could add in chopped onions, fresh garlic, a mix of cheese, or even a mix of mushrooms. Personalize this recipe and make it a family favorite using what YOU love!

Step by Step Instructions

This recipe requires minimal prepping, with your oven doing most of the work.

1. Preheat the oven to 375 degrees. Spray a casserole dish with nonstick spray, or wipe the inside down with a thin layer of olive oil.
2. Wash and pat dry the mushrooms. Slice the mushrooms and add them to the casserole dish. Sprinkle with salt and stir.
3. In a bowl, combine breadcrumbs, parmesan cheese, and garlic powder. Stir, then add the olive oil. Stir to combine, then drop over the tops of the mushrooms, eventually smoothing it out and covering the entire top of the dish. If desired, sprinkle a little more parmesan over the top.
4. Bake at 400 degrees for 20-25 minutes. Garnish with fresh chopped parsley and serve.

FAQ

Can I make a gluten-free unstuffed mushroom casserole?

Absolutely! I make this with gluten-free panko whenever my loved ones with gluten allergies are coming over, and honestly, you cannot tell a difference. Use the same measurement called for in the recipe.

Can I make this a main dish?

Yes! Adding crab or lobster to this would take it to a whole other level! Serving this over a seared steak or baked chicken would be amazing, too.

Tips for Making

Unstuffed mushroom casserole is an unexpected and tasty side dish paired with a grilled steak, pasta, or baked chicken. This would also make an excellent vegetarian sandwich filling!

Minimal prep is needed for this dish. If you want to put a little more time into it, switch the garlic powder for 2 fresh minced cloves of garlic.

If this casserole is too juicy for you, saute your sliced mushrooms for 10 minutes on medium-high heat before adding them to your casserole dish. This will cook out some of the water from the mushrooms before it goes into the oven.

Optional toppings are cooked, crumbled bacon or country sausage. You can also add more parsley or cheese as well.

Making Ahead and Storing Unstuffed Mushrooms

This dish is great to make ahead! You can prep the mushrooms and store in the fridge in an airtight container for up to 2 days before assembling and baking.

Store leftover unstuffed mushroom casserole in an airtight container. You can reheat in the oven or microwave until thoroughly warmed through. I do not recommend freezing this dish.

Love this Recipe? Try These Other Vegetarian Sides!

One Pot Orzo with Spinach and Mushrooms

Skillet Squash and Onions

Sesame Butterbean Salad

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