Grilled Balsamic Portobello Mushroom Burger

This classic grilled portobello balsamic portobello mushroom burger packs a flavor punch from an overnight marinade! Pop on the grill for an easy vegetarian summer main. Top with all your favorite burger toppings - my personal favorites are guacamole, tomato and feta.

Vegetarian Grilled Balsamic Portobello Mushroom Burger

Happy Fourth of July! Hope y'all are having a blast with family, friends and lots of obligatory red, white and blue food.

Independence day is one of my favorite food holidays. There's something special about hanging out with friends by the grill, enjoying your meal outside in the heat with an ice cold beer. And I just love the mix of rich cheesy and meaty foods, like ribs, burgers and mac and cheese, paired with lots of fresh salads and juicy watermelon.

Most of my July 4th memories growing up are at my dad's house. Every year he threw a massive pool party for his old fraternity brothers, basically a big college reunion. We would spend days cleaning and cooking massive batches of blue cheese coleslaw, pasta salad and cutting up chunks of fresh fruit in preparation...although my parents memory of how much I helped probably differs from mine.

The one monkey wrench was the fact that many of those years, I was a vegetarian. It was a hard thought decision I made based on strong morals and ethics...and by that I mean my best friend was a vegetarian so I had to be one too. This was always a hassle for my meat loving dad, who once proclaimed the five basic food groups to be chicken, beef, pork, lamb and seafood. Each meal had to have a vegetarian option that was grilling friendly. So let's just say I had a lot of portobello mushroom burgers.

Healthy Grilled Balsamic Portobello Mushroom Burger

How to Make a Portobello Mushroom Burger

Mushrooms have a meaty flavor, so burger-sized portobello’s are the perfect stand-in. The key is giving them a good bath in a flavorful marinade. Mushroom are a little spongy, so they soak up all the flavor you marinade them in. For this recipe, I did just a super simple blend of balsamic and olive oil seasoned with garlic and oregano.

All they need is a quick sear on a hot grill until marked and tender, about 4 minutes per side. Be sure to brush off the garlic before grilling, because it can burn on the grill, giving the mushroom a bitter flavor.

How to Top Your Grilled Balsamic Portobello Mushroom Burger

Any of your favorite burger toppings work great in this recipe, but I used guacamole, tomato and feta cheese because that’s what I had on hand! Here’s some other ideas:

  • Smashed avocado, grilled peppers and onions, and mozzarella cheese

  • Tomato, caramelized onions, Jack cheese and your favorite flavored mayo

  • Avocado, corn salsa, and sharp cheddar cheese

  • “California”-style with herbed goat cheese, tomato, red onion, cucumber, avocado and sprouts

  • Bacon (or veggie bacon), blue cheese and crispy onions

Get creative! Another one of my favorite ways to enjoy portobello burgers is to sandwich it with a frozen veggie burger (warmed, of course). It adds extra protein and makes the meal more satisfying if you’re feeling hungry.

Grilled Balsamic Portobello Mushroom Burger

Serves 4



  • 1/4 cup balsamic vinegar

  • 2 tablespoons extra-virgin olive oil

  • 5 garlic cloves, minced

  • 1/2 teaspoon dried basil

  • 4 portobello mushroom caps


  • 4 hamburger buns

  • 1 tomato, sliced

  • Guacamole

  • Crumbled feta


  1. In a large zip top bag, mix together balsamic, olive oil, garlic, and basil. Season with salt and pepper. Add portobello mushrooms and toss to coat. Refrigerate 8 hours to marinate.

  2. Heat grill on medium-high heat. Brush garlic off the mushroom caps to prevent burning, and grill mushroom caps four minutes per side until grill marked and tender. While mushrooms are grilling, lightly toast the buns on the grill.

  3. Serve portobello burgers on the bun with tomato slices, guacamole and feta.

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Grilled Balsamic Portobello Mushroom Burger! Meaty mushrooms marinated in balsamic vinaigrette are the perfect stand-in for beef! #burger #portobello #vegetarian #grilling #easyrecipe