clock clock iconcutlery cutlery iconflag flag iconfolder folder iconinstagram instagram iconpinterest pinterest iconfacebook facebook iconprint print iconsquares squares iconheart heart iconheart solid heart solid icon
one stuffed mushroom

Vegetarian Mashed Potato Stuffed Portobello Mushrooms

  • Author: amycaseycooks
  • Total Time: 40 minutes
  • Yield: 6 servings 1x


These vegetarian stuffed portobello mushrooms are so delicious and versatile. Roasted and stuffed with cheesy Parmesan mashed potatoes, they make a hearty meatless meal or unique and tasty side dish for just about any chicken, fish, beef or pork entrée.


Units Scale
  • 6 portobello mushrooms
  • extra virgin olive oil
  • kosher salt
  • pepper
  • garlic powder
  • 3 medium baking potatoes, about 2 pounds
  • 3 tablespoons salted butter
  • 2 tablespoons sour cream
  • 3/4 cup heavy cream
  • 1/2 cup grated Parmesan cheese, plus more for sprinkling on top
  • 2 tablespoons chopped fresh parsley
  • 2 thinly sliced scallions, green part only


  1. Preheat oven to 400 degrees F.
  2. Prep the mushrooms. With a paper towel, gently brush any dirt off the top of the mushroom caps. Flip over and remove the stems. Using a spoon, remove the gills from the underside of the mushrooms and discard.
  3. Place the mushrooms gill side down on a rimmed baking sheet. Drizzle with olive oil and sprinkle with kosher salt, pepper and garlic powder. Bake in the oven for 10 to 20 minutes. It will depend on how thick the mushrooms are. The mushrooms should be just soft, but still hold their shape. Remove from the oven and set aside. Increase the oven to 425 degrees F.
  4. While the mushrooms are baking, make the mashed potatoes.
  5. Peel the potatoes and cut into about 2 inch chunks. Place the potatoes in a large pot of water. They should be covered with about a couple inches of water.
  6. Place the pot of medium high heat and bring to a boil. Reduce the heat to a rolling simmer and continue cooking the potatoes until they can be easily pierced with a knife. Drain the potatoes and return them to the pot.
  7. Add the salted butter to the potatoes and mash with a potato masher. Add the sour cream and heavy cream and mash until creamy. Season with kosher salt and pepper. Add the Parmesan cheese and stir to combine.
  8. Flip the mushrooms over. Pour off any accumulated liquid on the baking sheet. Generously scoop some of the mashed potatoes on into the mushrooms. Sprinkle with more Parmesan cheese.
  9. Return the stuffed mushrooms to the oven. Bake for 10 to 15 minutes or until piping hot and browned on the top.
  10. Remove from the oven and sprinkle with parsley and scallions.


  • Portobellos come in different sizes and will roast at varying times. Keep an eye on them while they are in the oven. Smaller mushrooms will roast more quickly than the larger ones. You want the mushrooms to be tender yet hold their shape when cooked.
  • Choose high starch potatoes such as Russet and Yukon gold for the most delicious and fluffy mashed potatoes.
  • Mash the potatoes while they are hot. If the potatoes cool, they will be gluey and gummy when mashed.
  • Drain off any cooking liquid from the cooked mushrooms. The liquid will make the filling watery and unattractive.
  • Prep Time: 15 minutes
  • Cook Time: 25 minutes
  • Category: Side dish or entrée
  • Method: cook on stove top and bake in oven
  • Cuisine: American


  • Serving Size: 1 mushroom
  • Calories: 221
  • Sugar: 1.7 g
  • Sodium: 875 mg
  • Fat: 14.1 g
  • Saturated Fat: 8.5 g
  • Unsaturated Fat: 0 g
  • Trans Fat: 0 g
  • Carbohydrates: 18.4 g
  • Fiber: 4.3 g
  • Protein: 6.7 g
  • Cholesterol: 41 mg

Keywords: stuffed portobello mushrooms, vegetarian stuffed mushrooms, side dish ideas, vegetarian entrée ideas