Go Back
+ servings
Portobello Mushrooms with Acorn Squash Risotto

Portobello Steaks On A Bed of Acorn Squash Risotto & Garlicky Greens

Beautiful Portobello “steaks” with a balsamic marinade that adds a brightness to the meatiness of the mushroom, and really rounds out the dish.

Course Entree
Cuisine American
Prep Time 10 minutes
Cook Time 15 minutes
Total Time 25 minutes
Yield 4 servings
Calories 432 kcal
Author Natalie Wizer-Orozco


For the Portobellos:

  • 4 portobello mushroom caps
  • 3 tablespoons extra virgin olive oil
  • 3 tablespoons balsamic vinegar
  • ½ teaspoon salt
  • ¼ teaspoon freshly cracked black pepper
  • ¼ teaspoon red pepper flakes
  • 1 teaspoon finely minced garlic

For the Risotto:

  • 1 cup dry arborio rice
  • 2 tablespoons extra virgin olive oil
  • 1 ½ cup diced onion about 1 medium onion
  • 1 cup cooked acorn squash see notes
  • 2 cups vegetable stock
  • ¾ teaspoon salt
  • ¼ teaspoon freshly cracked black pepper
  • 1 bay leaf
  • 1 teaspoon fresh sage cut into thin ribbons

For the Garlicky Greens:

  • 8 cups fresh spinach 1 large bunch
  • 1 tablespoon finely minced garlic
  • 1 tablespoon olive oil
  • ¼ teaspoon red pepper flakes
  • ¼ teaspoon salt
  • pinch freshly cracked black pepper
  • pinch ground nutmeg


For the Portobellos:

  1. Turn the broiler on, and place the four portobellos cap side up on a baking sheet.
  2. Mix all of the ingredients, except the portobellos, in a bowl, mixing well. Using a pastry or bbq brush, liberally cover the portobello caps with the marinade. Turn the mushrooms over, then divide the remaining marinade, and pour into the gill side of each of the mushrooms. Using your brush, make sure the marinade gets into the gills. There should be a small pool of marinade in each of the mushroom caps.
  3. Place under the broiler, and let cook for 7 minutes, flip over so the cap side is up, and cook for an additional 4 minutes. Flip one more time, and finish under the broiler for 5 minutes more, or until cooked through. Remove from the oven, and cover with aluminum foil until ready to serve.

For the Risotto:

  1. While the portobellos broil, put the cooked acorn squash and vegetable stock in a blender, and blend until well combined.
  2. Place in a small sauce pan over low heat. Heat a medium sauce pan over medium – high heat, and add in the onions, and olive oil, cooking the onions for 7 minutes, until translucent and starting to turn golden in color, continually stirring.
  3. Add in the arborio rice, bay leaf, salt and pepper, and toast in the olive oil mixture for one minute.
  4. Add in one cup of the warmed acorn squash mixture, and mix with a wooden spoon until most of the liquid is absorbed, about 2-3 minutes.
  5. Turn the heat down to medium, and add in a half cup of the acorn squash mixture at a time, mixing until the liquid is absorbed each time, until all the liquid in the rice mixture is mostly gone, about 3 minutes per each liquid addition. Make sure to test the done-ness of the rice towards the end. If it's not quite al-dente, you may need more vegetable stock. With the last addition of the liquid mixture, mix only until you have a creamy consistency, add in the sage, and remove from the heat.

For the Garlicky Greens:

  1. Heat a saute pan over medium heat, and add in the garlic and olive oil, allowing the garlic to be come fragrant, about one minute.
  2. Add in the spinach, and turn with tongs, until all the spinach is just wilted, then remove from heat.
  3. Add in the salt, pepper, nutmeg and red pepper flakes. Toss until the spices are combined well.


  1. Divide the risotto among four shallow bowls, then layer the spinach on top, making sure to break up any spinach clumps.
  2. Cut the portobellos into strips, and place on top of the spinach.
  3. Garnish with small sage leaves, and serve!

Recipe Notes

For the cooked Acorn Squash, do the following:
Preheat the oven to 375°F. Cut an acorn squash in half, and scoop out the seeds. With a rimmed baking sheet, fill with water until it comes up about a quarter of an inch, and place the acorn squash cut side down. Place in the oven, and roast for 45 minutes to an hour, until the outside of the squash can easily be pierced with a fork. Remove from the oven and let cool, until cool enough to handle, and scoop out the flesh with a large spoon. Place the cooked squash in an air-tight container, and keep refrigerated until ready to use. Can be kept in the refrigerator for up to three days.