Shaved Portobello Mushroom Sandwiches
Prep time
Cook time
Total time
A Vegan take on the cold roast beef sandwich, this pan roasted Portobello mushroom sandwich comes with roasted onions and an awesome horseradish mayo
Serves: 1 sandwich
Per Sandwich:
  • 1 Ciabatta bun, split horizontally in two
  • 2-3 tablespoons Black Pepper-Horseradish Mayo (see below)
  • A small handful of baby spinach, tossed in a ¼ teaspoon olive oil and a tiny squeeze of lemon juice, salt and pepper to taste. Massage until lightly wilted.
  • 2-4 tablespoons prepared Pan Roasted Onions
  • 1 Pan Roasted Portobello mushroom, chilled and very thinly sliced on an angle. Think shaved roast beef as a guide
Black Pepper-Horseradish Mayo
  • Makes around ¾ cup, or enough for 4 sandwiches
  • 8 tablespoons/ ½ cup Vegan Mayo
  • 3 tablespoons concentrated mushroom drippings from a recipe ofPan Roasted Mushrooms (sorry, there is no substitute)
  • 1 tablespoon drained prepared horseradish
  • 1 ½ teaspoons Dijon mustard
  • ¾ teaspoon cracked black pepper
To Make the Black Pepper-Horseradish Mayo
  1. Combine everything in a bowl. It will stay fresh for around a week in the refrigerator
To Complete the Sandwich
  1. Toast the ciabatta halves in a hot, dry pan or under the boiler, until well toasted
  2. Spread both sides with a generous amount of the black pepper mayo, at least 2 tablespoons
  3. On the bottom half of the bread layer on some of the massaged baby spinach. Top with some roasted onions, then layer on the finely sliced Portobello mushrooms. Top with the other half of the ciabatta
Recipe by Two Happy Rabbits at