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one portobello mushroom sandwich on wooden board with 3 more blurred in the background

Portobello Mushroom Sandwich

These Portobello Mushroom Sandwiches are juicy, loaded with flavour and so easy to make!
5 from 1 vote
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Course: Dinner, lunch
Cuisine: Universal
Prep Time: 10 minutes
Cook Time: 25 minutes
Total Time: 35 minutes
Servings (click & slide): 4 sandwiches
Calories per serving: 326kcal
Author: Chris
Cost per serving: £2.50 / $3


  • Large Baking Tray
  • Small Pot (for garlic butter)
  • Sharp Knife & Chopping Board
  • Brush



  • 4 large Portobello Mushrooms (can sub large flat mushrooms of similar size - approx 3.5oz/100g each)
  • 4 tbsp / 2oz / 60g Unsalted Butter, melted
  • 1 tbsp very finely diced Parsley
  • 2 cloves of Garlic, very finely diced then mashed with the blade of your knife
  • 1/2 tsp Salt
  • 1/4 tsp Black Pepper


  • 4 Ciabatta Rolls, halved & toasted (see notes)
  • 4 heaped tbsp Hummus
  • 1/3 cup Caramelized Onions (see notes)
  • 2 large Roasted Red Peppers, sliced (see notes)
  • 4 pinches of Spinach/Rocket or greens of choice


  • Garlic Butter: In a small pot combine melted butter with parsley, garlic, salt and pepper.
  • Coat Mushrooms: Place mushrooms on a baking tray stalk side down. Brush them with garlic butter, then flip them over and brush the insides with the butter.
  • Bake Mushrooms: Place in the oven at 220C/450F for 20-30mins, or until fork tender. Timings will depend on the size of the mushrooms so just be vigilant. Tip out moisture gathered in the mushrooms if there's excess.
  • Sandwich: Spread hummus over the bottom half of the ciabatta. Add onions, then mushroom, followed by greens and roasted red peppers. Add the second half of the ciabatta, gently press down then enjoy!

Quick Demo


a) Ciabatta - This works great because it crisps up nicely and counteracts the soft mushroom and fillings. You can use any kind of burger bun or roll though. To toast them either add the halves to a scorching hot dry pan, or broil under the grill. Either way I highly recommend toasting the bread, just to add crispiness to the sandwich.
b) Caramelized Onions - Check out my Caramelized Onions recipe for guidance. If you're short on time just fry up some onion until golden. Alternatively you can add raw red onion if you want more of a pungent flavour.
c) Roasted Red Peppers - I use store-bought and just squeeze out the brine then pat dry with paper towels. However you can make your own, just char the peppers on a flame on the stove or place under the grill. Once charred all over and tender, place in a bowl with cling film over until cool enough to handle, then peel away the skin with most of the char. If you don't like peppers then sub tomato.
d) Calories - Per sandwich:

Your Private Notes:


Nutrition Facts
Portobello Mushroom Sandwich
Amount Per Serving
Calories 326 Calories from Fat 101
% Daily Value*
Fat 11.19g17%
Saturated Fat 5.411g34%
Polyunsaturated Fat 1.468g
Monounsaturated Fat 3.347g
Cholesterol 15mg5%
Sodium 657mg29%
Potassium 766mg22%
Carbohydrates 48.79g16%
Fiber 5.2g22%
Sugar 18.6g21%
Protein 10.69g21%
Vitamin A 1748IU35%
Vitamin C 80.7mg98%
Calcium 151mg15%
Iron 3.3mg18%
* Percent Daily Values are based on a 2000 calorie diet.
*Nutrition is based on the absence of salt unless stated as a measurement in the ingredients. Cost is worked out based on ingredients bought from UK supermarkets, then divided by the number of servings. In both instances these values are just for guidance. Please check out my FAQ Page for more info.
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