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portobello mushroom sandwich with basil on a plate

Portobello Mushroom Sandwich

Roasted Portobello Mushroom Sandwich with pesto mayo, tomatoes and feta. A quick and easy vegetarian sandwich recipe.
Course Lunch
Cuisine Vegetarian
Prep Time 5 minutes
Cook Time 15 minutes
Total Time 20 minutes
Servings 2
Calories 432kcal


  • 2 large portobello mushrooms wiped clean
  • 1 tablespoon olive oil
  • ½ tablespoon balsamic vinegar
  • ¼ teaspoon sea salt
  • ¼ teaspoon cracked black pepper
  • 3 tablespoon mayonnaise
  • ½ tablespoon vegetarian green pesto
  • 2 ciabatta rolls
  • 6 cherry tomatoes sliced
  • a small handful of basil leaves
  • ¼ cup feta cheese (25g)


  • Preheat the oven to 392F / 200C
    Brush both sides of the mushrooms with the oil then with the balsamic vinegar. Season with salt and pepper.
    Place the mushrooms stem side up on a small baking tray.
    Bake in the oven for 10 to 15 minutes.
  • Split the ciabattas in half, brush a little oil over each one then toast the inside of both pieces on a hot griddle pan. 
    Spread the mayo over the bottom ciabatta.
  • When the mushrooms are roasted, carefully pat them dry if they are very wet.
    Place one mushroom on each ciabatta. Crumble over the feta then add the tomatoes and a couple of basil leaves.
    Place the remaining ciabatta on top on then serve immediately.


  • Nutritional information is approximate.
  • The size of your portobello mushrooms will determine how long they take to cook. 
  • This is an easily scalable recipe, please see the serving size number in the recipe and slide it to the right to increase quantities.
  • If you want to make this recipe vegan, sub the mayo and pesto for vegan versions and sub the feta for a vegan alternative.
  • For a gluten-free version just use your favourite gluten-free bread and make sure the pesto is also gluten-free.


Calories: 432kcal | Carbohydrates: 20.1g | Protein: 10.2g | Fat: 34.9g | Saturated Fat: 7.3g | Cholesterol: 26mg | Sodium: 628mg | Potassium: 318mg | Fiber: 2.1g | Sugar: 1.4g | Calcium: 100mg | Iron: 1.3mg