Place the portabellini mushrooms, onion and thyme leaves in a food processor and blend to a paste.

Add the mince, Worcestershire sauce, breadcrumbs and a good grinding of salt and pepper and blend the mixture until just combined.

Divide the mince mixture equally into 4 balls and use your hands to carefully shape each ball into a burger patty.

Heat the oil in a griddle pan (or frying pan) and cook the patties for 4-5 minutes per side, or until cooked to your liking.

To assemble the burgers: cut the ciabatta rolls in half and toast under the grill for a few minutes until they start to brown.

Spread a tablespoon of onion marmalade on the bottom of each one.

Pile on some micro leaves or rocket followed by the burger patty and top with slices of brie cheese.

Serve with chunky fries.

Recipe courtesy of Cupcakes and Couscous