Step 1

Wash and clean the mushrooms. Mince them very finely.

Step 2

Heat 2 tablespoons of olive oil in a large frying pan. Add finely the sliced shallots and crushed garlic.

Step 3

Add the minced mushrooms. Fry gently for 2 mins.

Step 4

Add the marsala wine and finely chopped parsley.

Step 5

Cook for 10-12 mins until all liquid has evaporated.

Step 6

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.

Step 7

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.

Step 8

Make the caramelised onions just before you are ready to cook the burgers.

Step 9

Heat the olive oil and butter in a large frying pan. Add the sliced onions, sugar and vinegar. Stir a little.

Step 10

Leave to cook for 30-40 mins under gentle heat, stirring every now and then so the onions do not stick to the pan.

Step 11

When done, transfer to a serving bowl.

Step 12

Remove the mushroom mixture from the fridge. Mould handfuls of the mince mixture into burger patties. You should have 6.

Step 13

Heat some olive oil in a large frying pan. Cook the burgers for 10 to 12 minutes until evenly cooked. Turn them once.

Step 14

Serve with buns, salad, cheese and the caramelised red onions.