Balsamic Portobello Burger with Avocado and Spicy Mayo

Serving Size: 2
Total Time:

Juicy portobellos are so hearty, you wont miss the beef in these burgers. Seared and finished with balsamic glaze, Portobello mushrooms are served between warm buns topped with caramelized onions and spicy mayo. A side salad and creamy mashed avocado rounds out this hearty summer meal.


  • 2 portobello mushrooms
  • 2 burger buns
  • 2 Tbsp balsamic vinegar
  • 1 Tbsp hot sauce
  • 2 Tbsp mayonnaise
  • 1 avocado
  • 1 onion
  • 1 tomato
  • 2 Ounce arugula
  • 3 Tbsp olive oil


  1. Slice the onion and tomato into rings. The best way to do this is to slice a tiny sliver off one side so that the tomato and onion have a flat surface to lay on. Then slice in rings from end to end.
  2. Heat 1 tablespoon of olive oil in a pan over medium-low heat. When hot, add the onion and cook until soft and lightly brown. Keep them on the stove over low heat until the rest of the meal is ready.
  3. Brush the mushrooms with 1 tablespoon of olive oil and season well with salt and pepper. In a pan, cook the mushrooms over medium-high heat, smooth side down, for 6-8 minutes or until tender. Flip and cook another minute or two. Turn off the pan and add the vinegar. Cook for 1 more minute until caramelized. Coat the mushrooms in the glaze and set aside.
  4. Wipe the pan with a paper towel and toast the buns over medium-high heat for 3 minutes, flipping once, until lightly brown.  In a bowl, toss the arugula with 1 tablespoon of olive oil and season with salt and pepper.
  5. Halve, peel and pit the avocado. Then mash.
  6. Finish: In a bowl, combine the mayo with as much hot sauce as you’d like (it’s spicy!). Spread as much spicy mayo as you’d like on the buns. Layer a slice or two of tomatoes, a mushroom, and onions on one half of the bun and the mashed avocado on the other. Serve with arugula on the side.