Prepare all the ingredients.
Soak the porcini mushrooms in water according to the pack instructions.
Clean the fresh mushrooms and slice or chop.
Wash the parsley, shake dry and finely chop.
Peel and finely dice the onion.
Slit the meat lengthways and fold open. Cover with cling film.
Beat to an even thickness with a meat tenderizer. Season with salt.
Preheat the oven to 180°C (160°C fan, gas 4). Fry the onion in a pan until softened. Add the fresh mushrooms and cook briefly. Drain the porcini mushrooms, add to the pan and cook together for 2-3 minutes until the liquid has evaporated. Remove from the heat, season with salt and pepper and sprinkle with the parsley. Allow to cool.
Mix the breadcrumbs with the egg.
Spread on the meat.
Roll up and wrap with the bacon rashers.
Tie into shape with kitchen string and place on a baking tray. Cook in the oven for 1 hour 15 minutes. Remove the string and serve, cut into slices. Serve with baked potatoes and Brussels sprouts.