Jul 09 2026
RestaurantsTreehouse Pub & EateryPortobello Mushroom Sandwich Recipe

Portobello Mushroom Sandwich Recipe

Time1h
Serves2

Lettuce, tomato, onion, grilled pepper, avocado and melted white cheddar on a marinated portobello mushroom.

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Ingredients

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Mushroom Marinade

Sandwich Ingredients

Method

Marinating the Mushrooms

  1. 1

    Prepare the marinade

    In a small bowl, whisk together olive oil, balsamic vinegar, minced garlic, dried oregano, salt, and black pepper.

  2. 2

    Marinate the mushrooms

    Place the portobello mushrooms in a shallow dish and pour the marinade over them. Ensure the mushrooms are well coated. Cover and let them marinate for at least 30 minutes at room temperature.

Grilling the Mushrooms

  1. 3

    Preheat the grill

    Preheat your grill or grill pan over medium-high heat.

  2. 4

    Grill the mushrooms

    Remove the mushrooms from the marinade and place them on the grill, gill side down. Grill for about 5-7 minutes, then flip and grill for an additional 5-7 minutes until tender.

Assembling the Sandwich

  1. 5

    Prepare the vegetables

    While the mushrooms are grilling, slice the tomato, red onion, and avocado. Grill the bell pepper if not already grilled.

  2. 6

    Melt the cheese

    During the last minute of grilling, place a slice of white cheddar cheese on each mushroom and close the grill lid to allow the cheese to melt.

  3. 7

    Build the sandwich

    Toast the whole grain bread slices lightly. On the bottom slice, layer lettuce, grilled mushrooms with melted cheese, sliced tomato, red onion, grilled pepper, and avocado. Place the top slice of bread to complete the sandwich.

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