Pork Fillet Marinade and Farce: With a sharp knife make an incision through the centre of the fillet, pushing it through the whole length but not cutting through the end (be careful not to make any wholes through the fillet). Chop the mozzarella up roughly and mix in the basil. Fill the whole in the filets with the mozzarella and basil, pushing it through that it fills them completely. In a container large enough to hold the fillets mix the oils, garlic, thyme and seasoning together. Place the pork in the marinade and coat it well. Cover the pork and refrigerate for at least one hour.
Polenta Croutons: To cook the polenta bring the water or stock to the boil, then whisk in the polenta briskly so as to avoid lumps forming. Then mix it with a wooden spoon for 8-10 minutes. The polenta is ready when it is swollen and tender and comes away from the sides. Mix in the herbs, butter, Parmesan and a little salt, so that it is well distributed. Remove it from the heat and oil a tray thoroughly. Pour the polenta out onto the tray and spread out with an oiled palate knife, wooden spoon or clean hands so that it is evenly distributed and smooth. Set the polenta aside to set for at least 30 minutes. When set cut the polenta with a 5 cm round pastry cutter into croutons. Set aside; if preparing in advance refrigerate.
Mushroom Ragout: Reconstitute the dried mushrooms in 300ml of boiling water for 15 minutes. Then drain them reserving the water in which you soaked them. Roughly chop the wild and button mushrooms. Place the truffle and olive oil in a saucepan over a moderate heat and add the garlic and mushrooms and sauté for 5 minutes mixing regularly with a wooden spoon. Remove 2/3 of the mushrooms from the pan and set aside. Add the red wine and reserved mushroom water to the pan and increase the heat to high and bring it to the boil reduce the heat to a steady simmer then leave it to reduce until you have around 150ml liquid left (around 20 minutes). When reduced add the reserved mushrooms and set aside.
To Cook the Pork: Place the sawdust and rosemary in a smoker and place over a moderate heat until it begins to smoke. Reduce the heat slightly and place the pork on a rack in the smoker and cover. Smoke the pork fillets for 5 minutes on either side. Remove the pork fillets from the smoker and place them on an oven tray with a little olive oil and put in an oven heated to 220° C and cook for 8-10 minutes. Then remove form the oven, cover the fillets with foil and leave to rest for 5 minutes.
To Serve: Place the polenta croutons on a non stick or lightly oiled oven tray and place under a moderately high grill and cook for around 5 minutes, until the top is slightly golden and crisp and they are cooked through. Place 3-5 croutons on each plate. Reheat the mushroom ragout and put it over the polenta. Place the baby spinach on the plates. Slice the pork fillets diagonally and arrange on the salad in a fan like manner (Overlapping slices). Drizzle the truffle oil over the pork and mushrooms and place the Parmesan shaving around the plates. Serve