The Kitchn: You must make these grilled portobello burgers

It’s been over a month since I first made these plant-based burgers, and since then I’ve lost count of just how many times I’ve made them (it’s been a lot!). They’re juicy and easy and super satisfying, which is how they’ve won a spot in my dinner rotation.

Thick portobello mushroom caps (be sure to buy large ones!) are marinated and grilled until tender and lightly charred, then added on your favorite hamburger bun (which has already been swiped with pesto on both sides!) and layered with sweet and tender grilled red onion, roasted red pepper, and a small handful of spicy arugula.

They’re seriously satisfying and packed with flavor, and the mix of colors and textures will keep you coming back for more. This vegan sandwich checks all the boxes — and then some!

Is it OK to eat the gills of a portobello mushroom?

The gills on the underside of portobello mushrooms are totally edible and safe to eat. With some recipes, like stuffed portobello mushrooms, it’s helpful to scrape the gills out before cooking to make room for the filling, but when you’re making mushroom burgers that’s not necessary.

How do you prepare a portobello mushroom for grilling?

There’s very little prep involved in making portobello mushroom burgers. In fact, there are just two steps.

1. Marinate. Whisk together a simple pantry marinade, add the mushrooms, toss to coat, and let them sit at room temperature for about 30 minutes. (While the mushrooms are marinating you’ll have plenty of time to tear apart the roasted red peppers and slice and grill the red onion.)

2. Grill. This recipe includes the option to grill the mushrooms on an outdoor grill or using a grill pan on the stovetop. Regardless of the method you use, you’ll grill the mushrooms stem-side up until tender and grill marks appear, then flip and grill the other side until tender. If using a grill pan, plan on grilling the mushrooms in batches, as not to overcrowd the pan.

What should I serve with portobello mushroom burgers?

Any of your favorite sides to pair with burgers or sandwiches are a great addition with portobello mushroom burgers. Simple slaws and salads are good choice and I’m a fan of serving them with grilled vegetables since the grill’s already fired up.

Portobello Mushroom Burger

Serves 4

  • 2 cloves garlic
  • 4 large portobello mushrooms (about 3 ounces each and 4 inches wide)
  • 2 tablespoons balsamic vinegar
  • 1 tablespoon low-sodium tamari or soy sauce
  • 1 tablespoon olive oil
  • 1/2 teaspoon kosher salt
  • 1/4 teaspoon freshly ground black pepper
  • 1 small red onion
  • 4 ounces roasted red peppers (about 3/4 cup)
  • Vegetable oil
  • 4 hamburger buns
  • 1/2 cup vegan or regular pesto sauce (homemade or store-bought)
  • 1 cup packed baby arugula (about 1 ounce)

1. Mince 2 garlic cloves. If needed, remove the stems from 4 large portobello mushrooms.

2. Place the garlic, 2 tablespoons balsamic vinegar, 1 tablespoon low-sodium soy sauce, 1 tablespoon olive oil, 1/2 teaspoon kosher salt, and 1/4 teaspoon black pepper in a large resealable bag or large shallow container and stir to combine. Add 4 large portobello mushrooms and toss to coat. Marinate at room temperature for 30 minutes. Meanwhile, prepare the toppings.

3. Slice 1 small red onion into 1/4-inch thick rounds. Tear 4 ounces roasted red peppers (about 3/4 cup) into large pieces.

Option 1: Grill pan

1. Heat a grill pan over medium-high heat for 5 minutes. Brush the pan with vegetable oil. Place the onions in the pan in a single layer and cook until grill marks form on the bottom, 2 to 3 minutes. Flip the onions and cook until tender, about 2 minutes more. Transfer to a plate or baking sheet. Meanwhile, remove the mushrooms from the marinade.

2. Brush the pan again with vegetable oil. Working in batches if needed, place 2 of the mushrooms in the pan in a single layer, stem-side up. Cook until marks form on the bottom, about 4 minutes. Flip and cook until tender, about 4 minutes more. Transfer to a plate or baking sheet and tent with aluminum foil to keep warm. Brush the pan with more oil before cooking the remaining mushrooms.

3. If desired, split 4 hamburger buns and grill until toasted and lightly browned, 30 seconds to 1 minute per side.

Option 2: Outdoor grill

1. Prepare an outdoor grill for medium-high, direct heat. Scrape the grill grates clean if needed. Oil the grill grates with a paper towel dipped in vegetable oil.

2. Place the onions on the grill in a single layer. Cover and grill until grill marks form on the bottom, 2 to 3 minutes. Flip the onions and grill until tender, about 2 minutes more. Transfer to a plate or baking sheet. Meanwhile, remove the mushrooms from the marinade.

3. Place the mushrooms on the grill in a single layer stem-side up. Cover and grill until grill marks form on the bottom, about 4 minutes. Flip the mushrooms, cover, and grill until the mushrooms are tender, 3 to 4 minutes more.

If desired, split 4 hamburger buns and grill until toasted and lightly browned, about 30 seconds per side.

Finish

1. Spread 1/2 cup pesto evenly on the cut sides of the buns (about 1 tablespoon per bun half).

2. Place a grilled mushroom, stem-side up, on each bottom bun. Top the mushrooms with the grilled onion, roasted red pepper, 1 packed cup baby arugula, and close with the top bun.

(Kelli Foster is a senior contributing food editor for TheKitchn.com, a nationally known blog for people who love food and home cooking. Submit any comments or questions to editorial@thekitchn.com.)