How to cook
Trim the tenderloin. Chop and blend the mushrooms.
Rub the meat with all the listed ingredients for the marinade, including the mushrooms. Cover with cling film and allow it to rest in the fridge for at least 8 hours, or even longer, up to 48 hours if you have the time.
Once the fillet is marinated, take it out of the fridge and allow it to rest for 30 minutes at room temperature. In the meantime peel the potatoes and cut them lengthwise. If they are larger you can cut them into thick rounds. Make a few long shallow cuts on one side of each piece, and arrange them in a baking tray covered with parchment paper. Season with paprika, salt and a drizzle of olive oil. Leave some room in the middle of the tray for the tenderloin.
Preheat the oven to 360°F (180 degrees) and bake the pork fillet and potatoes for 30 minutes, until they obtain a gold brown crust. Since the cooking time may vary if the tenderloin is bigger, check with a toothpick towards the end of the cooking time - if the toothpick is inserted easily, the meat is cooked.
Allow it to rest for 5-8 minutes and slice the meat into thick rounds. Serve in a platter and garnish with the potatoes.
Enjoy your meal!