In a small bowl, whisk together the olive oil, vinegar and garlic. Brush each mushroom with the mixture making sure to cover completely. Let stand for 30 minutes.
Make the caramelized onions. Heat the olive oil in a large skillet to medium/high. Add in the onions, stirring frequently until softened, about 5-8 minutes. Reduce the heat to low, add the water and continue to cook slowly until browned, about 15 minutes. Add the balsamic vinegar and sugar, stirring occasionally until most of the liquid has evaporated. Season with the salt and pepper. Remove from the heat and cover.
Make the blue cheese mayo by thoroughly mixing together the crumbled blue cheese and mayonnaise. This creates a luscious, creamy garnish for the mushroom burger. Refrigerate until ready to assemble the burgers.
Preheat the grill to medium high. Gently season the top and bottom of each mushroom with salt and pepper. Lay the “gill” side of the mushroom onto the grill and cook for 4-5 minutes. Flip over and grill for another 4-5 minutes until the mushrooms are tender and caramelized.
To assemble the burger, put ¼ cup (5g) of arugula on the bottom of each bun (toasted if preferred). Generously top with a dollop of the blue cheese mayo and then lay the portobello mushroom “gill” side up. Add a good helping of caramelized onions and top with the bun and garnish with a cherry tomato using a toothpick to secure it in place.
In a small bowl, whisk together the olive oil, vinegar and garlic. Brush each mushroom with the mixture making sure to cover completely. Let stand for 30 minutes.
Make the caramelized onions. Heat the olive oil in a large skillet to medium/high. Add in the onions, stirring frequently until softened, about 5-8 minutes. Reduce the heat to low, add the water and continue to cook slowly until browned, about 15 minutes. Add the balsamic vinegar and sugar, stirring occasionally until most of the liquid has evaporated. Season with the salt and pepper. Remove from the heat and cover.
Make the blue cheese mayo by thoroughly mixing together the crumbled blue cheese and mayonnaise. This creates a luscious, creamy garnish for the mushroom burger. Refrigerate until ready to assemble the burgers.
Preheat the grill to medium high. Gently season the top and bottom of each mushroom with salt and pepper. Lay the “gill” side of the mushroom onto the grill and cook for 4-5 minutes. Flip over and grill for another 4-5 minutes until the mushrooms are tender and caramelized.
To assemble the burger, put ¼ cup (5g) of arugula on the bottom of each bun (toasted if preferred). Generously top with a dollop of the blue cheese mayo and then lay the portobello mushroom “gill” side up. Add a good helping of caramelized onions and top with the bun and garnish with a cherry tomato using a toothpick to secure it in place.
