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Blue Cheese Mushroom Burger With Caramelised Red Onions [vegetarian] by The Flexitarian

Blue Cheese Mushroom Burger With Caramelised Red Onions [vegetarian]

This Blue Cheese Mushroom Burger is a simple yet delicious recipe that gets the thumbs up from everyone at home.
5 from 1 vote
DieTARY CHOICEDairy-Free Recipes, High Fibre Recipes, Low Fat Recipes, Nut-Free Recipes, Soya-Free Recipes, Vegetarian Recipes
Prep Time 15 mins
Cook Time 1 hr
Resting Time 1 hr
Total Time 2 hrs 15 mins
Course Burgers, Meatless BBQ
Cuisine American
Servings 6 people
Calories 251 kcal


  • Frying pan
  • mixing bowl


  • 300 g chestnut mushrooms
  • 2 organic eggs
  • 100 g breadcrumbs - gluten free if needed
  • 60 g shallots finely sliced
  • 2 garlic cloves crushed
  • 4 Tbsp parsley - finely chopped
  • 175 ml marsala wine
  • 2 Tbsp olive oil
  • salt & pepper


  • 2 large red onions
  • 1 Tbsp olive oil
  • 1 Tbsp butter
  • 2 Tbsp brown sugar
  • 2 Tbsp balsamic vinegar


  • Buns of your choice
  • Blue cheese - or another cheese of your choice such as cheddar, goat cheese, smoked cheese etc..
  • Salad leaves, tomatoes, pickles etc..


  • Wash and clean the mushrooms. Mince them very finely.
  • Heat 2 tablespoons of olive oil in a large frying pan. Add finely the sliced shallots and crushed garlic.
  • Add the minced mushrooms. Fry gently for 2 mins.
  • Add the marsala wine and finely chopped parsley.
  • Cook for 10-12 mins until all liquid has evaporated.
  • Transfer the mushrooms to a bowl. Mix in the beaten eggs and breadcrumbs. You can use a bit more breadcrumbs if you feel the mix is too wet. Season to taste.
  • Set aside in the fridge for 1 hour so the breadcrumbs have time to soak up any extra liquid. The burger mixture can be made up to a day ahead and kept in the fridge in an airtight container.


  • Make the caramelised onions just before you are ready to cook the burgers.
  • Heat the olive oil and butter in a large frying pan. Add the sliced onions, sugar and vinegar. Stir a little.
  • Leave to cook for 30-40 mins under gentle heat, stirring every now and then so the onions do not stick to the pan.
  • When done, transfer to a serving bowl.


  • Remove the mushroom mixture from the fridge. Mould handfuls of the mince mixture into burger patties. You should have 6.
  • Heat some olive oil in a large frying pan. Cook the burgers for 10 to 12 minutes until evenly cooked. Turn them once.
  • Serve with buns, salad, cheese and the caramelised red onions.


Serving: 1burgerCalories: 251kcalCarbohydrates: 28gProtein: 6gFat: 10gSaturated Fat: 2gPolyunsaturated Fat: 1gMonounsaturated Fat: 6gTrans Fat: 1gCholesterol: 55mgSodium: 156mgPotassium: 406mgFiber: 2gSugar: 11gVitamin A: 85IUVitamin C: 4mgCalcium: 70mgIron: 2mg
Keyword blue cheese, burger, mushroom
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