Hamburgers belong to the category of dishes that create a mixed bag of feelings in which the delicious taste of meat and fries conflict with the countless disadvantages of fast-food or ultra-processed food. However, no one said that the filling of this American dish should be of beef origin. Cooking, like an artistic studio, encourages creativity. So we propose a recipe from the book Keep it Vegan written by Áine Carlin. The stuffing with portobello mushrooms and different condiments will make this dish an option open to those people with an animal conscience, who opt for calorie-free recipes to take care of their figure, or simply to innovate: Stuffed portobello mushroom burger with a touch of Dijon mustard, for four people.

You will need:

For the ketchup

  • 4 tomatoes
  • Half a teaspoon of ground pepper
  • 1 tablespoon vinegar
  • 1 teaspoon brown sugar
  • 1 tablespoon olive oil, salt and freshly ground black pepper

For the side dish

  • 4 large potatoes
  • 2 teaspoons Dijon mustard
  • 2 tablespoons oil
  • 1 teaspoon vinegar
  • 1 sprig of chopped rosemary

For the mushroom Burger

  • 1 tablespoon olive oil
  • 30g butter or vegan margarine
  • 4 portobello mushrooms
  • 1/2 onion, diced
  • 1 clove garlic, minced
  • Sprig of thyme, chopped
  • 100g breadcrumbs
  • 30g vegan butter or margarine
  • 1 tablespoon red wine vinegar
  • 25g pine nuts, toasted
  • 15g fresh parsley, chopped
  • 4 ciabatta rolls, halved
  • Rocket leaves, for garnish

Once we have the ingredients:

1.Preheat the oven to 200ºC.

2. Place the tomatoes on a sheet of parchment paper. Sprinkle with a teaspoon of salt and pepper, the vinegar, brown sugar and oil. Roast for one hour. Remove from the oven and allow to cool before passing through a sieve. Season and put in the fridge until needed (the ketchup will keep for two days).

3. Cut the potatoes into thick slices and place in a bowl. Whisk together the Dijon mustard, oil, vinegar, rosemary, a teaspoon of salt and some freshly ground black pepper. Pour the mixture over the pieces and toss to coat completely. Roast for one hour, shaking the pan from time to time to prevent the pieces from sticking. Season again when removed from the oven.

4. For the burger filling, heat the oil and butter/vegan margarine in a medium non-stick frying pan and add the onion. Season and sauté gently until it begins to soften. Remove the stems from the mushrooms, finely chop and add to the pan. Sauté the onion and mushroom stems for a minute or two before adding the garlic and thyme. Season generously and cook for a few more minutes.

5. Add the breadcrumbs to the pan along with the vegan butter/margarine and red wine vinegar. Allow the breadcrumbs to brown for a few minutes before adding the toasted pine nuts and chopped fresh parsley.

6. Lightly grease the baking tray. Brush the mushrooms with oil and season with salt and pepper on the outside. Divide the breadcrumb mixture between them and press them together well with the back of a spoon or your fingers. Place them on the baking tray and put them in the oven for the last 30 minutes of cooking.

7. Spread each bun with a little ketchup and serve the mushrooms on them with a handful of rocket leaves and the potatoes on the side.


Finally, all that’s left to do is enjoy a burger with an original twist.