Cook the mushrooms in a non stick frying pan without oil stirring for 8-10 minutes to drive off all the moisture
Whizz together the onion courgette carrot and nuts in a processor until they are beginning to bind together
Stir in the mushrooms breadcrumbs parsley yeast extract and seasoning to taste Shape into burgers with lightly floured hands and chill
Cook the burgers in a non stick frying pan with very little oil or under a hot grill for about 8-10 minutes turning once until they are cooked and golden brown