Preheat the oven to 200 °C conventional oven/ 180°C fan-forced (400° Fahrenheit/Gas 6).
Place the porcini mushrooms in a small bowl, cover with boiling water and leave to soak for 10 minutes.
Prepare the paper parcels for the salmon by cutting four 30cm x45cm sheets of baking paper. Fold each baking sheet in half across the middle. Fold three of the sides up, sealing the edges by brushing them with melted butter before folding. Folding it twice over and firmly, leaving one side open to add ingredients.
Heat a shallow frying pan over medium heat and add half of the olive oil until hot. Add the garlic and fry until lightly coloured. Add the white wine and allow to gently evaporate while stirring. Meanwhile remove the porcini mushrooms from the water, reserving the liquid which has become darker in colour and concentrated with porcini flavour.
Add the porcini mushrooms to wine liquid, then add the vegetable stock and porcini liquid. Bring to the boil, then reduce heat to low until the liquid has evaporated (approximately 7-8 minutes). Transfer the mushrooms and cooking liquid from the frying pan to a bowl and set aside.
Wipe the frying pan with paper towel. Heat the remaining olive oil over medium heat. Season the salmon fillets and cook for half a minute on each side then remove from the heat.
Place the salmon and an even number of raw prawns into the paper parcel. Spoon the porcini mushrooms and liquid over the salmon and sprinkle with parsley. Seal the edge by folding twice over.
Optional – Wrap each of the parcels with kitchen string and tie a bow for presentation.
Place the parcels on a roasting tray and bake for 12-15 minutes or until the salmon is cooked through. Serve by placing the Salmon and baby prawns ‘al cartoccio’ (in paper parcel) on a plate and opening the parcel – buon appetito.