4 Portobello Mushrooms
4 Ciabatta Buns
1/2 cup Balsamic Vinegar
1/4 cup Olive Oil
1/2 cup vegan or regular mayo
1/4 cup creamy horseradish sauce
1 teaspoon Kosher salt and ground black pepper
1 cup vegan or regular shredded cheese
1 cup baby arugula
Marinate the mushrooms in the olive oil and vinegar for 30 minutes or overnight.
Roast in the oven at 425 degrees F. for 15 minutes.
In a small bowl, mix together the mayo and horseradish sauce. Season with salt and pepper.
Assemble the sandwich with the cooked mushroom, sauce, arugula, and cheese.