Photo: Oxmoor House
4 servings

While making your own veggie burger patties from-scratch can be complicated, these easy portobello mushroom burgers keep vegetable-forward grilling feeling simple. Meaty and rich in savory flavor, marinated and grilled portobello mushrooms make for the perfect vegetarian burgers. For this flavor-packed burger recipe, half of a roasted bell pepper is stirred into mayonnaise for a zesty sandwich spread. You can use the leftover bell pepper as a pizza topping, in salad, tossed with pasta or even as a fresh topping for your mushroom burgers.

How to Make It

Step 1

Combine first 4 ingredients in a large zip-top plastic bag; add mushrooms to bag. Seal and marinate at room temperature for 2 hours, turning bag occasionally. Remove mushrooms from bag; discard marinade.

Step 2

Prepare grill to medium heat.

Step 3

Cut bell pepper in half lengthwise; discard seeds and membranes. Place pepper halves on grill rack coated with cooking spray; grill 15 minutes or until blackened, turning occasionally. Place in a zip-top plastic bag; seal. Let stand 10 minutes. Peel. Reserve 1 pepper half for another use. Finely chop 1 pepper half; place in a small bowl. Add mayonnaise, 1/2 teaspoon oil, and ground red pepper; stir well.

Step 4

Place mushrooms, gill sides down, on grill rack coated with cooking spray; grill 4 minutes on each side. Place buns, cut sides down, on grill rack coated with cooking spray; grill 30 seconds on each side or until toasted. Spread 2 tablespoons mayonnaise mixture on top half of each bun. Place 1 mushroom on bottom half of each bun. Top each mushroom with 1 tomato slice and 1 lettuce leaf; cover with top halves of buns.

Ratings & Reviews

cookinfabulous's Review

January 01, 2009
These were awesome - the red pepper sauce really made them special. As a vegetarian, I'd be thrilled if someone served these to me, but I don't think meat eaters would find the mushroom a suitable replacement to the burger - maybe the mushroom AND the burger with the sauce.

Runner3375's Review

November 30, 2008
Mmmmm! I LOVED this meal. I have been replacing meat with vegetarian options and I can honestly say that the flavor was so delicious that I didn't miss hamburger at all. I will definitely make this again! (Try it on the grill - it's outstanding!)

bellymama's Review

June 26, 2011
Nice meat-free option for a simple meal. I served the portobello burgers with baked sweet potato fries and fresh melon. I cut the roasted red pepper into strips insted of putting them in the mayo. Next time I will leave out the mayo and use some goat cheese.

HeatherN's Review

April 30, 2013
Fantastic- cooked Costco's huge mushrooms, added munster cheese, definitely a repeat.

jspicest's Review

April 13, 2014
These were absolutely delicious. I followed the recipe exactly. I agree that the noon role is crucial. We served with roasted cauliflower and oven-baked sweet potato fries. Great combo!

AliyahH's Review

December 12, 2011

DB1967's Review

November 27, 2012

killoran's Review

July 04, 2012
Caramelized onions and a slice of Swiss cheese (if you're not vegan) are also very special on these burgers. That's how I usually do them, instead of the mayo and roasted red pepper. (I'll have to try that, though, since it's getting such good reviews.) The marinade is what makes these so special. Brush or pour a little extra on while they're grilling. If you're cooking for one, like I usually do, a small zipper freezer bag is great for marinading.

MeMyselfAndPie's Review

November 19, 2010
Who knew a die hard meat-loving husband would melt over a mushroom burger?! The marinade makes them so juicy and flavorful, and the mayo is the perfect compliment. One thing - make sure you serve them on onion rolls like stated. They're perfect for this recipe! Review and photos on my blog:

IODizzee's Review

June 20, 2010
This recipe is delicious! Quick prep time as well.