Grilled Portobello Burgers
These grilled portobello burgers are the perfect vegetarian alternative to your favorite beef burger. Bathed in balsamic vinegar, Worcestershire sauce, and olive oil, these ‘shrooms have no shortage of flavor!
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Although I enjoy a juicy burger or steak occasionally, I’m not a big meat eater. Enter these grilled portobello burgers over their all-beef cousin when those veggie cravings strike. Or this peppers and eggs sandwich.
Über flavorful with a delicious concoction of balsamic vinegar, Worcestershire sauce, olive oil, garlic powder, and a dash of smoked paprika, you almost don’t miss the meat here—or maybe not at all if you’re a die-hard vegetarian.
Just because these burgers are mushroom-based doesn’t mean they don’t include the common burger fixings. They’re bulked up with sliced tomato, red onion, and peppery arugula, and they’re covered with a melted blanket of baby Swiss. The mild, nutty flavor of the Swiss balances nicely with the stronger marinade, but feel free to use any cheese you like, such as Gouda or Gruyère.
Of course, these toppings are fully customizable, and I vary them myself from time to time. Garnish with some creamy avocado (yum!), grilled or sautéed red onions (or any onions), lettuce, or a dollop of basil pesto if you’re feeling fancy.
Let’s start grillin’ some ‘shrooms!
Why You’ll Love These Grilled Portobello Burgers
- They’re a great vegetarian burger option: Even if you’re not a strict vegetarian but occasionally enjoy vegetarian versions of meat-based classics, a mushroom burger never fails.
- They have a bit of everything on one bun: Flavors: Smoky, sweet, slightly bitter, nutty. Texture: Soft, smooth, crispy, crunchy.
- They’re easy to prepare: With little more than some slicing and assembling a quick marinade, this recipe is quick and easy.
Ingredients You’ll Need
- Portobello Mushroom Caps: They’re the “meat” of this burger.
- Balsamic Vinegar: This vinegar’s milder flavor works well as part of the marinade.
- Worcestershire Sauce: This gives an underlying umami flavor to the burger.
- Extra Virgin Olive Oil: EVOO imparts maximum flavor to the marinade.
- Garlic Powder: This works wonders in infusing the marinade with a distinct garlic taste.
- Smoked Paprika: Don’t substitute with regular paprika; the smoky version is more pronounced.
- Baby Swiss: Nutty, this cheese complements the stronger flavors of the burger nicely.
- Arugula: This provides a sharp and peppery bite and is recommended over standard greens.
- Hamburger Buns or Sandwich Thins: Use your favorite bread to hold this burger together.
- Large Tomato: Vine or beefsteak tomatoes are good choices.
- Red Onion: If you prefer a different onion on your burger, use it.
See the recipe card below for more information on ingredients and quantities.
How to Make Grilled Portobello Burgers
- Marinate the mushroom caps: Pour all the liquid ingredients along with the garlic powder and smoked paprika in a large ziploc bag. Add the mushroom caps. Seal the bag and shake it to mix the ingredients and coat the mushroom caps. Let sit for 20 to 30 minutes.
- Cook the mushroom caps: Heat a grill pan and cook the mushroom caps until soft and tender, about 5 minutes per side. Repeat the process and cook each side for about another 3 minutes each. Sprinkle each side with salt and pepper.
- Prepare the toppings: Slice the tomato and red onion, and assemble the arugula and baby Swiss.
- Add the cheese: Top each mushroom cap with the baby Swiss and cook until the cheese melts. Cover the pan with a lid to contain the heat.
- Assemble the burgers: Layer the burgers with the arugula, portobello mushrooms, tomato slices, and sliced red onion.
Pro Tips
Clean the mushroom caps with a soft-bristled brush: A damp paper towel will also work. Don’t rinse or clean them under running water, as this will only contribute to the mushrooms’ already high water content.
Salt the mushroom caps near the end of their cooking time: Adding salt too early makes the mushrooms release more water, and they won’t caramelize and develop flavor as well.
Lightly toast the hamburger buns, if you’d like: This will help them hold up to the burgers better.
Suggestions for Variations and Substitutions
- Use any cheese you like: Regular Swiss, Gouda, Gruyère, mozzarella, and provolone are all good.
- Add additional toppings, such as avocado, basil pesto, sun-dried tomatoes, and roasted red peppers.
- Use sandwich thins instead of hamburger buns for a lower carb option.
Recipe FAQs
Traditional hamburger buns are classic, but you can also use hearty rolls. Another option is to use sandwich thins (this is featured in the above hero image); they’re surprisingly sturdy and allow the burger flavor to really come through.
The easy answer is any cheese you like! But if you need some direction, Swiss, Gruyère, and pepper Jack are great options. Other ones are provolone, Gouda, and mozzarella, including the smoked varieties.
Storage
Refrigerator
These grilled portobello burgers are best eaten immediately, but you can save the mushroom caps (without the buns) in an airtight container in the refrigerator for up to 2 days.
Freezer
I don’t recommend freezing any part of a portobello mushroom burger.
Reheat
Gently reheat the mushroom caps in the oven at 350F max to re-melt the cheese. If you stored any mushroom caps without cheese, reheat the caps first until heated through, then add the cheese and continue heating until the cheese melts. I recommend placing the mushroom caps on fresh hamburger buns.
More Quick Recipes
- White pizza panini
- Italian peppers with olives and breadcrumbs
- Zucchini and eggs
- Sardines on toast
- Cod puttanesca
If you love this recipe, please take a moment to review it below. You could also tag me on Instagram (@forcarbssake) with a picture of your finished dish!
Grilled Portobello Burgers
Ingredients
- 2 portobello mushroom caps cleaned
- 2 tablespoons balsamic vinegar
- 2 teaspoons Worcestershire sauce
- 1 teaspoon extra virgin olive oil
- ½ teaspoon garlic powder
- ⅛ teaspoon smoked paprika
- ½ teaspoon kosher salt divided
- 4 slices Swiss cheese baby variety, divided (Note 1)
- Arugula handful
- 2 hamburger buns or sandwich thins
- 2 to 4 sliced tomatoes large (Note 2)
- 4 to 6 slices red onion
Instructions
- Place the mushroom caps in a large ziploc bag along with the balsamic vinegar, Worcestershire sauce, extra virgin olive oil, garlic powder, and smoked paprika. Seal the bag and gently shake and massage it to evenly distribute the marinade. Let the mushroom caps sit for 20 to 30 minutes, turning the bag over at least once to ensure even coating.2 portobello mushroom caps, cleaned; 2 tablespoons balsamic vinegar; 2 teaspoons Worcestershire sauce; 1 teaspoon extra virgin olive oil; ½ teaspoon garlic powder; ⅛ teaspoon smoked paprika
- Heat a grill pan over medium-low to medium heat. Once hot, remove the caps from the bag, shake off any excess marinade, and place them on the grill pan. Start by cooking each side for 5 minutes, flipping again and cooking for about another 3 minutes per side until they develop nice grill marks and flatten a bit. Wait until they're just about done before sprinkling each side with some kosher salt and pepper–use ⅛ teaspoon kosher salt per side.½ teaspoon kosher salt, divided (1/8 teaspoon per side)
- Top each mushroom cap with 2 slices of baby Swiss cheese. Place a lid over them (make sure it's large enough to cover both caps), and cook until the cheese melts, about 2 minutes. 4 slices Swiss cheese, baby variety, divided
- Place a small handful of arugula on the bottom of both buns. Place each mushroom cap on top of the bed of arugula. Top each cap with 1 to 2 tomato slices and 2 to 3 sliced red onion (both depending on thickness and preference). Enjoy! Arugula, handful; 2 hamburger buns or sandwich thins; 2 to 4 sliced tomatoes, large; 4 to 6 slices red onion
