Parmesan Mushroom Casserole


Mushrooms are sprinkled with a crunchy, cheesy panko topping to create a delicious mushroom casserole that all will love.

Active Time:
35 mins
Total Time:
1 hr

What Variety of Mushrooms Can I Use?

We use baby bella mushrooms for the recipe, which are also called cremini mushrooms. Baby bella mushrooms are the same variety as white button mushrooms but are slightly more mature and brown in color. They are firm in texture with a mild, earthy flavor. If you can't find baby bella mushrooms, portabello mushrooms would be a good alternative.

Do You Bake This Casserole Covered or Uncovered?

Casseroles that are made with cooked ingredients are typically baked uncovered. This allows moisture to be released to prevent the casserole from getting too soggy. Baking the casserole uncovered also helps crisp and brown the surface. We cook the mushrooms in a large skillet to release some of their moisture, then the casserole is baked uncovered until bubbling and the panko breadcrumb mixture is browned and crispy.

What to Serve with Parmesan Mushroom Casserole

This simple side dish can be prepared for a holiday meal or a weeknight dinner and pairs well with many main dishes, including Crispy Roast Chicken & Carrots, Grilled Filet Mignon with Herb Butter & Texas Toasts, Bacon-Wrapped Pork Tenderloin with Honey-Almond Green Beans, Garlic Roasted Salmon & Brussels Sprouts and Herb-Roasted Turkey Breast with Garlic.

The mushroom casserole can also be the main course when paired with Couscous & Chickpea Salad, Apple-Cranberry Spinach Salad with Goat Cheese, Farro Salad with Arugula, Artichokes & Pistachios or Wild Rice Salad with Arugula Pesto.

Additional reporting by Jan Valdez


  • ¼ cup extra-virgin olive oil plus 1 tablespoon, divided

  • 1 cup chopped onion

  • 3 cloves garlic, minced

  • 2 pounds baby bella mushrooms, sliced

  • 3 tablespoons all-purpose flour

  • ¾ teaspoon salt

  • ½ teaspoon ground pepper

  • ½ cup sour cream

  • ¼ cup Parmesan cheese plus 1 tablespoon, divided

  • ¼ cup chopped fresh parsley plus 1 tablespoon, divided

  • 1 tablespoon lemon juice

  • ¼ cup panko breadcrumbs


  1. Preheat oven to 350°F. Coat an 8-inch-square baking dish with cooking spray.

  2. Heat 1/4 cup oil in a large skillet over medium heat. Add onion and cook, stirring, until soft and starting to brown, about 3 minutes. Add garlic and cook, stirring, for 1 minute. In batches, add mushrooms, stirring and allowing them to cook down a bit before adding another handful, until they've lost their opaqueness but some liquid is still in the pan. Sprinkle flour, salt and pepper over the vegetables and cook, stirring, until thickened, 1 to 2 minutes. Remove from heat and stir in sour cream, 1/4 cup Parmesan, 1/4 cup parsley and lemon juice. Transfer to the prepared baking dish.

  3. Combine panko and the remaining 1 tablespoon each oil, Parmesan and parsley in a small bowl; mix with your fingers until well blended. Sprinkle the topping evenly over the mushroom mixture. Bake until bubbling and the breadcrumbs are lightly browned, 20 to 25 minutes.

    Parmesan Mushroom Casserole
    Photography / Brie Passano, Styling / Sammy Mila / Holly Raibikis


8-inch-square baking dish

To make ahead

Prepare through Step 2 and refrigerate for up to 2 days. Let stand at room temperature while the oven preheats.

Nutrition Facts (per serving)

229 Calories
17g Fat
15g Carbs
8g Protein
Nutrition Facts
Servings Per Recipe 6
Serving Size ¾ cup
Calories 229
% Daily Value *
Total Carbohydrate 15g 5%
Dietary Fiber 2g 7%
Total Sugars 5g
Protein 8g 16%
Total Fat 17g 22%
Saturated Fat 4g 20%
Cholesterol 13mg 4%
Vitamin A 377IU 8%
Sodium 387mg 17%
Potassium 580mg 12%

Nutrition information is calculated by a registered dietitian using an ingredient database but should be considered an estimate.

* Daily Values (DVs) are the recommended amounts of nutrients to consume each day. Percent Daily Value (%DV) found on nutrition labels tells you how much a serving of a particular food or recipe contributes to each of those total recommended amounts. Per the Food and Drug Administration (FDA), the daily value is based on a standard 2,000 calorie diet. Depending on your calorie needs or if you have a health condition, you may need more or less of particular nutrients. (For example, it’s recommended that people following a heart-healthy diet eat less sodium on a daily basis compared to those following a standard diet.)

(-) Information is not currently available for this nutrient. If you are following a special diet for medical reasons, be sure to consult with your primary care provider or a registered dietitian to better understand your personal nutrition needs.

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