Mushrooms Au Gratin

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

This mushroom gratin is made with browned cremini mushrooms, a creamy sour cream sauce, and a layer of melted Swiss cheese. It's a rich, savory side dish that's especially good with steak, roast beef, or chicken.

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.

These make a wonderful side dish to a boneless prime rib or a standing rib roast. A nice green vegetable side rounds out the meal nicely and adds some needed color to your plate (try green beans almondine).

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.

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!

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, shiitake, 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.
• 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.

Continue to Content

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.

4.5 Stars (10 Reviews)

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Ingredients

• 2 tablespoon extra-virgin olive oil
• 2 lbs fresh cremini mushrooms, sliced thick
• ⅔ cup sour cream
• 1 – 2 tablespoon flour
• ¼ teaspoon coarse salt
• a few turns of freshly ground black pepper
• 1 cup shredded cheese (suggested: Swiss)
• ¼ cup chopped fresh parsley

Instructions

1. Preheat the oven to 400°F.
2. Heat a large skillet over medium-high heat. Add the olive oil, then the
   sliced mushrooms. Cook until the mushrooms release their moisture, the liquid
   evaporates, and the mushrooms begin to brown. Avoid crowding the pan; cook in
   batches if necessary.
3. In a small bowl, whisk together the sour cream, flour, salt, and black
   pepper until smooth.
4. Reduce the heat to low. Stir the sour cream mixture into the browned
   mushrooms and cook for about 1 minute, stirring constantly. Remove from the
   heat.
5. Transfer the mushrooms to a greased baking dish and sprinkle the shredded
   Swiss cheese evenly over the top.
6. Bake for 15–20 minutes, until the cheese is melted and beginning to turn
   golden.
7. Sprinkle with chopped fresh parsley and serve warm.

Notes

• Browning the mushrooms: Use a large skillet and let the moisture evaporate before stirring frequently. Browning adds flavor and prevents a watery gratin.
• Mushroom varieties: Cremini or baby bella mushrooms work especially well. White button mushrooms are an easy substitute.
• Cheese: Swiss is a good choice, but Gruyère or fontina can also work. Use a cheese that melts smoothly.
• Sauce: Reduce the heat before adding the sour cream mixture, and stir gently to help keep the sauce smooth.
• For a creamy sauce: Turn down the heat before stirring in the sour cream mixture. You want it to coat the mushrooms without boiling vigorously.
• For the best topping: Look for melted cheese with a few golden spots around the edges. If the top needs more color, a brief turn under the broiler can help—just watch it closely.

Nutrition Information:

Yield: 4 Serving Size: 1
Amount Per Serving: Calories: 554Total Fat: 36gSaturated Fat: 17gUnsaturated Fat: 19gCholesterol: 85mgSodium: 573mgCarbohydrates: 38gFiber: 2gSugar: 6gProtein: 24g

This data was provided and calculated by Nutritionix.

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Kristy Bernardo

Kristy Bernardo is a recipe developer, five-time cookbook author, and founder of The Wicked Noodle. A former personal chef and cooking instructor with Culinary Institute of America (Hyde Park) boot-camp training and IACP membership, she creates approachable home-cooked recipes.

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