If you like mushrooms, you’ll love mushroom burgers. These grilled portobello burgers are piled with vegetables and finished with basil aioli. An easy vegetarian burger recipe.
A few weeks back I served Scott and Emily a completely vegetarian meal and it was really good — but to them, it felt like more of a side dish. Not that it wasn’t tasty. It was. Not that it didn’t fill them up. It did. To them, however, it just seemed like there should be a piece of chicken or a pork chop on the plate as well. So it was with some trepidation that I embarked on this menu: portabella burgers.
Mushrooms naturally have a meaty quality to them, a savoriness and even a juiciness that makes them a perfect stand-in for a regular burger. But how would my carnivorous family react? I felt that if mushrooms were going to be a substitute for beef, then the toppings and condiments had better perform like the special sauce on a Big Mac — with gusto!
I love peeled, roasted bell peppers and thought they would add a light sweetness to the burgers. Ripe tomatoes? Check. Grilled red onion? Check. And for a little bitter crunch, I settled on raddichio. Scott and Em prefer cheese on their burgers and I had several kinds in the fridge. Cheddar, possibly. Pepper-jack was another option. I ended up grating some smoked gouda for another umami layer. It needed a sauce, but ketchup and mustard didn’t seem right. I had a whole bunch of beautiful basil and decided a basil aioli would straddle the line between bright and fresh and decidedly indulgent. I began prepping the mushrooms and other vegetables.
That’s when Emily came in the kitchen and announced that her friend, Miranda, was coming for dinner. Uh oh. Siccing a vegetarian meal on my family was one thing, but on poor, unsuspecting Miranda? Maybe I should have some ground chuck on standby.
Grow a spine, Lisa. If they didn’t like it, they could have a bowl of cereal later. Emily set the table while Scott grilled the veggies and toasted the buns. I did the remainder of prep and we sat down to eat.
First, let me say, visually, the colors were beautiful. My diners assembled their burgers according to their own tastes and I heard nary a complaint. In fact, everything was devoured. The basil aioli, which was referred to by the girls as Green Goddess Sauce, was a big hit. No leftovers. No complaints. No bowl of cereal. Success.
Grilled Portobello Burgers
- 3 red bell peppers
- 8 portabella mushroom caps stemmed
- 1 red onion sliced crosswise into 1/2" slices
- 1 1/2 cups smoked gouda or cheddar or pepper jack, shredded
- 3 cloves garlic minced divided in half
- 1/4 cup olive oil
- 1 tablespoon worsterschire sauce
- 1 tablespoon balsamic vinegar
- 1/2 teaspoon kosher salt
- 1/2 teaspoon black pepper freshly ground
- 8 whole wheat hamburger buns or rolls
- 1 cup mayonnaise
- 1 cup fresh basil leaves
- remainder of garlic
- squeeze lemon about 1 tablespoon
- Heat oven to 375 degrees. Place bell peppers on a baking sheet and roast for 30 minutes until flesh is softened and skin is blackened. Remove peppers from oven and place in a small glass bowl. Cover bowl tightly with cellophane. Let peppers cool until they are comfortable to handle. Peel the skins from the peppers. Pull peppers apart into large chunks and discard seeds and stems. Set aside.
- While peppers cook, use a spoon to scrape the gills from the underside of the mushroom caps. Set aside.
- In a small bowl combine olive oil, worstershire, balsamic, garlic, salt and pepper. Whisk to combine.
- For aioli: In a blender or mini-prep food processor add basil leaves, garlic and 3/4 cup of mayonnaise. Pulse until basil is incorporated into the sauce. Add a lemon and pulse again (note: I have a Vitamix blender which can turn concrete into a frothy drink - which is why the color of my aioli is green. With a regular blender/food processor, it probably won't achieve the same color, but the flavor will be there. Promise.) Scrape aioli into a small bowl -- it may look curdled. Add the remainder of the mayonnaise and whisk briskly. The aioli should smooth right out.
- Heat a grill to a medium high heat - about 375-400 degrees. While grill heats brush mushroom caps and onion slices with marinade.
- Grill mushroom caps and onion until flesh is softened and exterior begins to take on some grill marks. About 8-10 minutes.
- Toast six buns on the grill for just a few minutes, until lightly browned.
- Build burgers. Spread basil aioli on the top and bottom buns. Place mushrooms on the buns, dress with a sprinkle of cheese, a few onion rings and roasted red pepper and tomato.
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