---
title: Portobello Burgers
source:
  name: HelloFresh
  url: https://www.hellofresh.com/recipes/portobello-burgers-5739e67cf8b25ecc468b4567
servings: 2
prep time: 10 minutes
cook time: 15 minutes
time required: 25 minutes
difficulty: Easy
allergens:
  - Eggs
  - Milk
  - Soy
  - Wheat
tags:
  - Spicy
  - Veggie
rating: 3.5
rating_count: 822
source_chef: Recipe Development Team
review_highlights: []
image: "https://images.recipes.furrysalamander.com/Mushroom%20Recipes/Portobello%20Mushrooms/portobello-burgers.avif"
---
Wash and dry all produce. Peel the @yellow onion{1%unit}, then slice end-to-end into thin rings and separate them. Thinly slice the @roma tomato{1%unit} into rounds. In a #small bowl{}, combine the @mayonnaise{2%tbsp} and as much @hot sauce{1%tsp} as you like.

Heat a drizzle of @olive oil{2%tbsp} in a #large pan{} over medium heat. Add the onions and cook, tossing for ~{4%minutes}, until softened and slightly golden. Season with @salt{1%tsp} and @pepper{1%tsp}. Remove from the pan and set aside.

Heat the same pan over medium heat. Rub the @portobello mushrooms{2%caps} on each side with olive oil and season with salt and pepper. Add them to the pan and cook for ~{4%minutes} per side, until very soft. Add 1 ½ tbsp @balsamic vinegar{3%tbsp} to the pan for another ~{1%minute}, until the vinegar reduces by half. After tossing the portobellos in the balsamic glaze, remove from the pan and set aside.

Toast the @potato buns{2%unit}: Split the buns. Clean out the same pan and heat over medium-high. Add the buns to the pan cut-side down and toast for ~{3%minutes}, until golden brown.

Halve, pit, and scoop the @avocado{1%unit} flesh into a #small bowl{}. Mash with a fork and season to taste with salt and pepper.

Finish and serve: In a #medium bowl{}, toss the @arugula{1%cups} with a drizzle of olive oil, the remaining balsamic vinegar, and a pinch of salt and pepper. Spread the buns with the spicy mayo and top with the portobello caps, tomato rounds, onions, and mashed avocado. Serve the arugula salad to the side and enjoy!