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

5 from 2 votes

Portobello Mushrooms with Acorn Squash Risotto

This is my second year contributing to October Unprocessed, and I can’t even begin to explain how thrilled I am!  Whenever I think of October Unprocessed, a few major topics come to mind.

First, is: Vegetarian.  I am a meat eater, but I always try to include more awesome vegetarian dishes into my husband and I’s diet – dishes that will excite us so much, that we don’t miss the meat one bit!  October Unprocessed is the perfect catalyst to get excited about vegetarian dishes.

Second is: Fall.  It IS October, after all, and everyone is excited for those signature fall flavors.  Pumpkin, earthy, herbaceous, and warm spices come to my mind.

This year, I opted for a different winter squash – the Acorn Squash.  In the past, I’ve made pumpkin risotto, but the pumpkin gets so much attention this time of year, I thought I’d give the acorn squash the spotlight this time.  The squash gives the risotto this beautiful extra creamy texture without adding any dairy, and it’s delightful!

I love adding greens to my dishes, and we do just that with the garlicky spinach.  It adds a beautiful texture, and slight pungent flavor to the risotto with the addition of garlic.

Finally, during fall everyone seems to want hearty dishes.  That’s where the star of the dish comes in – beautiful portobello “steaks”!  The balsamic marinade adds a brightness to the meatiness of the mushroom, and really rounds out the dish.

Portobello Steaks Acorn Squash RisottoWhile this dish may be a little more involved, it is completely worth it!  My advice is to take the time on a leisurely Sunday afternoon while watching football or the food network, and make this dish.  It will make your Sunday dinner special!

Portobello Mushrooms with Acorn Squash Risotto
5 from 2 votes

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

By: Natalie Wizer-Orozco
Beautiful Portobello “steaks” with a balsamic marinade that adds a brightness to the meatiness of the mushroom, and really rounds out the dish.
Prep: 10 minutes
Cook: 15 minutes
Total: 25 minutes
Servings: 4 servings


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:

  • Turn the broiler on, and place the four portobellos cap side up on a baking sheet.
  • 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.
  • 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:

  • While the portobellos broil, put the cooked acorn squash and vegetable stock in a blender, and blend until well combined.
  • 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.
  • Add in the arborio rice, bay leaf, salt and pepper, and toast in the olive oil mixture for one minute.
  • 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.
  • 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:

  • 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.
  • Add in the spinach, and turn with tongs, until all the spinach is just wilted, then remove from heat.
  • Add in the salt, pepper, nutmeg and red pepper flakes. Toss until the spices are combined well.


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


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.


Calories: 432kcal, Carbohydrates: 53g, Protein: 7g, Fat: 21g, Saturated Fat: 3g, Sodium: 1406mg, Potassium: 813mg, Fiber: 4g, Sugar: 5g, Vitamin A: 6080IU, Vitamin C: 21.5mg, Calcium: 80mg, Iron: 4.4mg
Like this recipe? Rate and comment below!


About the Author

Natalie Wiser-Orozco is a computer scientist by day, and recipe developer, photographer, and writer for The Devil Wears Parsley by night. She uses the website as a platform to “feed your inner rock star,” which means nourishing yourself with awesome, organic, local, fresh, whole foods with the occasional indulgence, so you can continue to rock at life! Follow Natalie on Facebook and Instagram.

A photo of Andrew Wilder leaning into the frame and smiling, hovering over mixing bowls in the kitchen.

Welcome to Eating Rules!

Hi! My name is Andrew Wilder, and I think healthy eating doesn’t have to suck. With just three simple eating rules, we'll kickstart your journey into the delicious and vibrant world of unprocessed food.

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March 6, 2016 5:31 pm

This recipe was delicious. My kids even loved it. I cooked the acorn squash earlier in the day. Having done that, the prep didn’t feel like it was a long time. I make risotto often so I am used to the constant stirring and the patience. . . It’s worth it!

November 5, 2014 1:30 pm

5 stars
Ab-so-lute-ly fantastic. I’ve just made this dish. I had some pumpkins that were in need of being used for something (not acorn squash, but it worked just fine). Followed the exact instructions with all the right ingredients, with the exception of simply cooking the pumpkin in water. The result is a fantastic dish in perfect harmony. Only one thing I need to keep in mind for next time is to take it easy with the red pepper flakes. I got some dried red peppers that were a lot heftier than I anticipated, but fortunately I love spicy food.
This is one for the favourites list.

November 4, 2014 5:31 am

Since when can we make oil in our own kitchens? That’s the test for unprocessed, right? Being oil-free isn’t that difficult. And if you’re unprocessed, you should be oil-free, IMO. Much healthier for you.

Reply to  K8L
November 4, 2014 9:11 am

It wouldn’t be too difficult to make olive oil at home – though you’d need a press designed to do it, it’s not particularly process-intensive or technical (unlike most refined oils, some of which use hexane and other solvents, or enzymatic reactions). Butter (from grass-fed cows, preferably), lard, tallow, nut oils, and unrefined coconut oil are also possible at home with a little effort.

As to whether or not someone “should” be oil-free, oil is indeed a concentrated source of calories, so I do agree it’s best to include oil sparingly if at all.

October 23, 2014 5:44 pm

Made this tonight and it was excellent. The rice does take a long time to cook….patience needed! I marinated the mushrooms but waited to cook them until I had the spinach going. Long prep time, lots of pans but worth it.

October 20, 2014 11:38 am

5 stars

October 20, 2014 11:34 am

Oh my goodness – do you deliver? Oh, ok. This does sound like it’s worth an afternoon in a scented, warm kitchen…

October 20, 2014 9:43 am
Heather Bee
October 20, 2014 8:45 am

Thank you! I’ll be trying this! I have a lonely acorn squash at home and I was wondering what to do with it 🙂