Grilled Balsamic Mushrooms with Polenta

Grilled Balsamic Mushrooms with Polenta with garlic, thyme, balsamic vinegar, and Parmesan cheese all cooked on the grill in 10 minutes. Jump to Recipe

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Grilled Mushrooms marinated in balsamic vinegar, thyme, and Parmesan cheese and served with polenta makes the most delicious vegetarian main dish or side.

The first thing that comes to mind when I think about vegetarian grilling is portobello mushrooms. With their meaty texture and earthy flavor, they are one of my favorite things to put on the grill. However since mushrooms don't really make for a complete dinner, I always find myself spending too much time in the kitchen cooking up the rest of the meal. That all changes with this dish. And polenta on the grill - next level good.

To get things started, let's talk about the mushrooms. Before grilling them, it's best to add as much flavor as you can. I like to do this with a quick marinade of balsamic vinegar, soy sauce, garlic, and red pepper flakes. The soy sauce adds some needed salt but also adds a savory note they works really well with mushrooms. The red pepper flakes add a nice spicy note but can be left off if you don't like heat. You can also add any kind of herbs you like to this mixture - rosemary, thyme, oregano, marjoram, or basil would all work. And make sure not to throw away your marinade, it is delicious drizzled on the final dish.

Next up is the polenta. To keep things quick and easy, I like to buy the packaged polenta. It normally can be found near the pasta and usually comes in a round tube. You can buy it with or without flavorings, the sundried tomato version is really tasty with this dish. You can also make your own and refrigerate it into squares. Now the trick to making awesome polenta on the grill is to make sure it is coated with a good helping of olive oil to prevent sticking. This will allow the polenta to crisp up on the outside and stay nice and creamy on the inside. Delish.

Then toss everything on a bed of greens, peppery arugula is perfect, and top with your favorite cheese. Delicious and easy.

Grilled  mushrooms with polenta on a plate with Parmesan cheese and arugula.

How to grill mushrooms?

  1. Always start by cleaning your mushrooms with a moist paper towel to clean off any excess dirt or debris. You can also wash whole mushrooms in water, just make sure to dry them well after washing. Sliced mushrooms absorb lots of water, so if you wash them, it is best to dry them with a salad spinner immediately after. One other tip - mushrooms get slimy if they sit for too long after being washed. Always wash them right before using them.
  2. Add some flavor to your mushrooms with a marinade. We love using olive oil, balsamic vinegar, soy sauce, and herbs but anything will work. Experiment with different dressings, herbs, spices, and vinegar. 
  3. Preheat the grill. Having the grill nice and hot will ensure a nice sear and grill marks on the mushroom.
  4. Prepare the mushrooms for the grill. Large mushrooms can go directly on the grill but smaller mushrooms may need to be skewered together or cooked in a grill basket.
  5. Generally speaking, mushrooms take about 8-10 minutes to grill and you will want to flip them halfway through the cooking process.

Tips for Making Grilled Balsamic Mushrooms with Polenta

  • Mushrooms: Although I love portobellos for this recipe, any mushroom with work. For smaller mushrooms, consider using a grill basket to make sure they don't fall through the grates of the grill. If you hate mushroom, eggplant is a good substitute.
  • Herbs: The marinade can be doctored up using any combination of fresh or dried herbs. Rosemary, thyme, oregano, marjoram, basil, or parsley are all good options. And make sure to save the marinade to drizzle over the mushrooms and polenta when they come off the grill.
  • Cheese: We had a bunch of fresh parmesan in the house so I opted to use that, however, there are so many good cheese options for this dish. Consider trying it with goat cheese, feta cheese, blue cheese, fresh mozzarella, or gorgonzola.
  • Polenta: For the fastest preparation, go for the premade polenta that is sold in the grocery store. If you have more time or have polenta at home, you can make it from scratch and then chill it. Once it is chilled, cut it into squares and these can be used on the grill.

Looking for other mushroom recipes?

Here are some of the tools and products I used to prepare these Grilled Balsamic Mushrooms with Polenta:

  • If you don't have a gas or charcoal grill at home, a grill pan is a great option for grilling indoors. I used one for years when I lived in an apartment that didn't allow grills. The two that I use most often are this nonstick version and this cast iron version. The nonstick is great for easy clean-up but the cast iron will give you deeper grill marks and more smoky flavor.
  • High-quality balsamic vinegar: Since the balsamic vinegar is one of the main flavors in this recipe, it's really important to choose a high-quality one that will pack in the flavor and bring the right amount of sweetness and tartness. This doesn't mean you have to spend a fortune though. Personally, I usually buy Whole Foods 365 Aged Balsamic Vinegar and also enjoy this one and this one.
  • Polenta: There are all kinds of options when it comes to premade polenta. Usually, I buy mine at Trader Joe's or the grocery store. I have also tried this version from Amazon and its really good as well.
The Recipe
Grilled balsamic mushrooms and polenta with Parmesan cheese and arugula.

Grilled Balsamic Mushrooms with Polenta

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  • 6 U portobello mushrooms
  • 1/4 cup balsamic Vinegar
  • 2 tbsp fresh thyme, minced
  • 1 tbsp low sodium soy sauce
  • 2 U cloves garlic, minced
  • 1/16 tsp red pepper flakes
  • 18 oz. prepared polenta
  • 2 tbsp olive oil
  • 2 cups arugula
  • 1/4 cup Parmesan cheese
  • Salt and pepper

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Mix together the balsamic vinegar, thyme, soy sauce, garlic, red pepper flakes, salt, and pepper. Marinate the mushrooms in this mixture for at least 30 minutes.


When ready to cook, remove the mushrooms from the marinade letting excess drip off. Grill for 4-5 minutes per side until cooked through on a grill or grill pa. You can also cook them in a cast iron or heavy skillet.


Cut the polenta into slices. Brush with olive oil and season with salt and pepper. Grill for 4-5 minutes per side or until it no longer sticks.


Serve the cooked mushrooms with the polenta and arugula. Sprinkle with Parmesan cheese. You could also drizzle some of the leftover marinade over the top.

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Nutritional Facts
Serving Size: 1 cup
Amount Per Serving
Calories 204
Calories from Fat 79
% Daily Value *
Total Fat 9g
Saturated Fat 2g
Monounsaturated Fat 0g
Polyunsaturated Fat 0g
Cholesterol 5mg
Sodium 642mg
Total Carbohydrate 24g
Dietary Fiber 2g
Sugars 5g
Protein 6g

* Percent Daily Values are based on a 2,000 calorie diet. Your daily values may be higher or lower depending on your calorie needs.

The Nutritional Values provided are estimates only and may vary based on the preparation method.

† SmartPoints™ calculated by Slender Kitchen; Not endorsed by Weight Watchers International, Inc.
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About the author Meet Kristen Mccaffrey
Hi, I’m the cookbook author, recipe developer, and food enthusiast behind Slender Kitchen. I am obsessed with making healthy food that is easy to prepare and absolutely delicious. Meal planning is my secret weapon and I hope I can make meal time easier for you with our tired and tested recipes and foolproof meal plans. Learn More
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