Pesto Portabello Mushroom Burgers

Portobello Mushroom Burger

Not long after having my third child I was talking to a friend about how overwhelmed I was, explaining that I could no longer keep the “to dos” straight in my head. With the various activities, play dates, nap times, and many appointments, along with my own schedule, I wasn’t able to keep track of it all.

With a look of compassion towards my bedraggled postpartum self, my friend leaned in and asked, “Are you writing all of these things down?”

“You mean, like, make a list?” I asked quizzically. I’d never done that before.

But I’d also never had three kids before and all the robbing of brain cells that goes along with it.

Anyway, it was genius. Write it down. I’ve been a mad list-maker ever since.

With one exception: The grocery store. I rarely use a shopping list. I know, I know. Not having a list leads to impulse purchasing, overspending, forgetting things you need. But the market, whether it’s the grocery store or the farmer’s market is where I get my inspiration. I poke around and see what grabs my eye: a particularly glossy piece of fish, a creamy wedge of cheese, a head of gorgeous lettuce, and the ideas for what I’m going to cook that night bubble up.

A Meaty Mushroom

Such was the case the day I made these Pesto Portabello Mushroom Burgers. I had a hankering for a burger, but wasn’t in the mood for meat. And it needed to be quick. Portabello mushrooms seemed the perfect answer, albeit a little “1990s”, having largely gone the way of sun dried tomatoes and raspberry vinegar.

I hadn’t grilled a portabello mushroom in years, but passé or not, they’re delicious. And so easy. Once that grill is hot, this meal could qualify as a 15-minute fix: Dinner from start to finish in a quarter of an hour. If you don’t want to bother with the barbecue, you can cook them under a broiler.

Good for You

Portabellos are just mature Cremini mushrooms, the common brown variety. Rich in minerals, particularly selenium, copper and potassium, they are very low in calories (about 20 calories a pop).

The texture of the mushrooms offers a meatiness that truly satisfies, and can hold up to a generous bun and flavorful pesto. In this case, I used a loaf of herbed focaccia cut into squares and toasted on the grill. I had some yellow peppers on hand which I charred and then peeled. You can always use peppers from a jar, but if you’ve never roasted your own, it’s worth a go. The kids might like to try their hand at peeling the blackened skins from the peppers. Here is a quick tutorial I found on You Tube that might prove helpful.

Lots of Burger Appeal

When the burgers are grilled or broiled and tucked between the focaccia along with all of the other goodies, they look just as compelling as any meaty number. Upon learning there was a mushroom under that bun and not a patty of beef, my daughter Rosie threw me that look kids give when you are about to feed them something new and different and perhaps a little strange. But one bite in and she exclaimed, “Delish, mom”!

Portobello Mushroom Burger

Grilled Portabello Mushroom Burgers

The texture of the mushrooms offers a meatiness that truly satisfies, and can hold up to a generous bun and flavorful pesto. You can always use peppers from a jar, but if you've never roasted your own, it’s worth a go. When the burgers are grilled and tucked between the focaccia along with all of the other goodies, they look just as compelling as any meaty number.
Course Main Course
Prep Time 15 minutes
Cook Time 10 minutes
Total Time 25 minutes
Servings 4 servings
Calories 300 kcal
Author Katie Morford


  • 4 large portabello mushrooms, stems removed, washed
  • 1 tablespoon extra-virgin olive oil
  • 2 teaspoons balsamic vinegar
  • Salt
  • Freshly ground black pepper to taste
  • 4 generous slices Mozzarella cheese
  • 1 loaf focaccia bread, cut into 4 burger-sized squares and split down the center
  • Prepared basil pesto
  • 2 small roasted red or yellow bell peppers, split in half*
  • 1 large handful baby arugula or spinach
  • 4 large slices tomato (more if tomatoes are small)


  1. Heat up the grill to medium-high or turn on the oven broiler with the rack at the highest level. While the grill./broiler are heating, drizzle the oil and vinegar over the mushroom caps and rub all over with your hands. Season liberally with salt and pepper.

  2. Put the mushrooms, cap-side-down, on the hot grill (set on a baking sheet and put under a broiler, if using). If grilling, cover the grill. Cook until they look quite tender on one side without burning, about 5 minutes. Turn over, cover (if grilling), and cook on the second side for 3 to 5 minutes until tender but not shriveled. For the last minute of cooking, set a slice of cheese on each mushroom to melt. Toast the buns on the grill or in the oven.

  3. Remove the buns and mushrooms. Spread a thin layer of pesto on the top and bottom of each bun. Set the mushrooms on each of the bottom buns. Top with the peppers, followed by the tomatoes and arugula or spinach. Serve immediately.

Recipe Notes

*You can find roasted bell peppers sold in jars in most markets or you can roast your own (a quick Google search will turn up plenty of instructions).


08.04.2011 at4:42 PM #

Pamela Prime

Oh yum…I really look forward to preparing this! Thank you.

08.06.2011 at12:27 AM #


Being a bit on the scattered side in food preparation, your 15 minute meal is my 30 minute meal – which is still quick enough for me. But I’m curious, do you peel the charred peppers within that time? I remember charring and peeling peppers for a soup, and they were delicious, but it was no small feat.

08.06.2011 at12:27 AM #

Katie Morford

Yes…maybe I’m pushing the limits of 15 minutes on this one. Probably more achievable if you are using a jarred pepper, which I often do. Roasting your own peppers makes it more time consuming, for sure. That said, if you set the pepper on the grill at the same time as you do the mushrooms, it shouldn’t take too long. I often char my peppers on the flame of my stove as well.

03.18.2024 at6:17 PM #

Joy Randel

You mention tomatoes at the end as a topping but tomatoes are not listed in the ingredients.

03.18.2024 at6:17 PM #

Katie Morford

I just added them. Thanks for noticing. You just want to slice them as you would for any burger.

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