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Mushrooms Au Gratin

Mushrooms au Gratin are a delicious and different way to serve mushrooms. They make a wonderful side dish!

Mushrooms Au Gratin

I adore mushrooms. Doesn’t matter to me how they’re prepared, what type of mushroom it is, or if it’s appetizer, entrée, or dessert (okay, even I draw the line at dessert…maybe). Add a sour cream mixture and a layer of cheese? I’m in food heaven. 

The trick to getting the most flavor from your mushrooms is to cook them over HIGH heat. You almost want to think of your meaty mushrooms as a nice, juicy steak…put them in a very hot pan, and don’t touch them for at least a few minutes, and preferably after they’ve released all their moisture and it’s evaporated. You want to get a nice, golden color before flipping them – that’s how you’ll build the most flavor.

Mushrooms Au Gratin Ingredients

  • Cremini Mushrooms: Cremini mushrooms have a firm, meaty texture. These are often labeled as baby bellas.
  • Olive Oil: For sauteing the mushrooms. You can sub in avocado oil, vegetable oil, or butter if necessary.
  • Sour Cream: This creates the creamy liquid mixed into the mushrooms.
  • Flour: Flour thickens the sour cream sauce.
  • Salt & Pepper: Salt & Pepper always enhances the flavor of your dish.
  • Shredded Cheese: We recommend swiss to add the delicious cheesy layer to your au gratin. You can also use jack, mozzarella, or provolone.
  • Fresh Parsley: Fresh herbs always add a special touch to you dishes.
Mushrooms Au Gratin

How To Make Mushrooms Au Gratin

(Scroll down to the bottom for the printable recipe card with exact measurements and recipe instructions.)

This is a great mushroom recipe that even my kids will eat (well, one of them). The leftovers heat up very nicely and taste just as good as when they’re fresh out of the oven. I hope you enjoy them!

  • Preheat your oven to 400F and heat your skillet over medium high heat.
  • Add olive oil and, once simmering, add the mushrooms to the pan. Cook the mushrooms until they’ve released their liquid and are well browned.
  • Mix the sour cream and flour together with salt and pepper and add the mixture to the pan with the mushrooms. Continue cooking for one minute while stirring, then turn off the heat.
  • Pour the mushrooms and sour cream mixture into a greased baking dish, top with cheese, and bake for 15-20 minutes or until the cheese is melted and browning.
  • Top with fresh chopped parsley and serve!

What To Serve With Mushrooms Au Gratin

Mushrooms au gratin is a great side dish that is perfect for both a fancy holiday meal, or even a comforting weeknight meal. Here are a few things that pair well with mushrooms au gratin:

Mushrooms Au Gratin Substitutions & Variations

Mushrooms au gratin are best made with sour cream and shredded Swiss cheese. But if you need to make a few swaps or want to try a few variations, here are some tips:

  • Mushrooms: While we recommend the cremini or baby bellas, you can use any type of mushroom you’d like in this recipe including white mushrooms, shitake, oyster, a mix of wild mushrooms, dried porcinis, or even large portabellas. If you use large mushrooms, just be sure to slice them into bite sized pieces first.
  • Cheese: We recommend swiss, but you can use any cheese that you prefer, such as fontina, gruyere, mozzarella, cheddar, havarti, and gouda. You can even throw in some parmesan if you’d like.
  • Dairy Free: Can you make these dairy free? Yes. It won’t be the rich, cheesy au gratin that is expected, but if you want a vegan or dairy free alternative, you can whisk together a slurry of coconut cream or almond milk with garlic, arrowroot powder, mustard, and nutritional yeast to make a thick, creamy sauce, and top with vegan cheese if you prefer.
  • Additions: add some thinly sliced potatoes or onions, leeks, bacon, diced chicken, or even spinach.
  • Toppings: For a little crunch, you can add crushed breadcrumbs, croutons, crackers, or panko. And I like to top everything with green onions.
  • Herbs: Other herbs that go well with mushrooms au gratin are rosemary, thyme, and sage.

Prep, Storage & Reheating

  • This can be made up to 24 hours ahead of time. Once you pour it into the baking dish, cover it tightly with a lid or plastic wrap, then put in the fridge until you are ready to bake.
  • You can also prebake it, then warm it in the oven once you get to your destination.
  • If you have leftovers, place it in an airtight container and store it in the refrigerator for up to 3-5 days.
  • Not my favorite method, but you can freeze mushrooms au gratin in an air tight container in the freezer for about a month. Just thaw in the fridge overnight before reheating.
  • To reheat in the microwave, add your portion to a bowl, and zap in the microwave for about one minute. Then try 30 second bursts until heated through.
  • To reheat on the stove, add mushrooms au gratin to a skillet with a touch of butter or olive oil, and warm on low until heated through, stirring occasionally.
  • To reheat in the oven, add to a baking dish, and heat in the oven or toaster oven at 350F until heated through.
Mushroom Gratin

Mushrooms au gratin

Yield: 4 servings
Prep Time: 5 minutes
Cook Time: 30 minutes
Total Time: 35 minutes

An easy, cheesy side dish that's perfect with grilled chicken or steak.


  • 2 tbsp extra-virgin olive oil
  • 2 lbs fresh cremini mushrooms, sliced thick
  • 2/3 cup sour cream
  • 1 – 2 tbsp flour
  • 1/4 tsp coarse salt
  • a few turns of freshly ground black pepper
  • 1 cup shredded cheese (suggested: Swiss)
  • 1/4 cup chopped fresh parsley


  1. Preheat the oven to 400°F.
  2. Preheat a large skillet over medium-high heat. Add the oil and, when it's shimmering, add the mushrooms. Cook until they've released their liquid and it's evaporated, then they've started to brown.
  3. Mix together the sour cream and flour, whisking to make sure the flour is well-incorporated. Stir in the salt and pepper..
  4. Add to the sour cream mixture the pan. Cook for one minute, stirring constantly. Turn off the heat.
  5. Transfer the mixture to a greased baking dish. Top with cheese and pop it in the oven. Bake for 15-20 minutes or until the cheese is melted and starting to brown.
  6. Sprinkle with the parsley and serve.
Nutrition Information:
Yield: 4 Serving Size: 1
Amount Per Serving: Calories: 419Total Fat: 35gSaturated Fat: 18gTrans Fat: 1gUnsaturated Fat: 14gCholesterol: 81mgSodium: 449mgCarbohydrates: 16gFiber: 2gSugar: 5gProtein: 14g

This data was provided and calculated by Nutritionix.

Find more mushroom recipes here!

Kristy Bernardo
Latest posts by Kristy Bernardo (see all)


Friday 24th of June 2022

Can't wait for leftovers (only 2 of us in house!) to put over baked potato!!! Another fave potato topping is asparagus in bechamel sauce, too!


Thursday 25th of October 2012

Oh my gosh these sound amazing!! I love mushrooms prepared in so many ways, this one is new to me. What a great side dish to so many things.

the wicked noodle

Friday 26th of October 2012

eek!! This is one of my oldest posts and the photos are slightly embarrassing! I may have to update this soon. But the mushrooms really are delish!


Wednesday 3rd of March 2010

Hi guys,

I know this might be a bit off topic but seeing that a bunch of you own websites, where would the best place be to host. Someone recommended I use Blue Host for $6.95 a month which seems like a great deal. Anyone here on using them?

the wicked noodle

Monday 11th of January 2010

Mushrooms tend to soak up any moisture in a pan pretty quickly, so your butter shouldn't burn. I've never had any problems, but you if you're concerned you can always add a bit of olive oil to the butter and that will give you a higher smoke point.


Sunday 10th of January 2010

Do we saute the mushrooms in butter, or just throw them in the pan? Won't the butter burn at that temperature?

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