Pork roll with mushroom filling

Ingredients:

• 7 tbsp. l. olive oil
• 450 g wild mushrooms (such as oyster mushrooms and/or ram's-head mushrooms), trimmed and sliced
• 1 small head of garlic, crushed
• 0.5 cup finely chopped parsley
• 1 tbsp finely chopped thyme + 2 sprigs
• 1 tbsp finely chopped rosemary + 1 sprig
• 1 boneless pork tenderloin (weighing 1.5-2 kg)
• 1/4 tbsp. dry sherry
• 1 cup lightly salted chicken broth
• 1 tbsp (15 g) butter

Preparation:

1. Adjust oven racks in the lower and upper thirds of the oven and preheat to 350°F (175°C). Heat 1 tablespoon olive oil in a large nonstick skillet over medium-high heat. Add the mushrooms and cook until browned, about 2 minutes. Stir and continue cooking, stirring occasionally, until tender, another 4 to 5 minutes. Push the mushrooms to one side of the skillet. Add another 1 tablespoon olive oil and the garlic to the other side of the skillet and cook, stirring occasionally, until softened, about 30 seconds. Stir the garlic into the mushrooms and season with salt and pepper. Let cool.
2. Meanwhile, in a small bowl, combine parsley, chopped thyme and rosemary, 3 tablespoons olive oil and a pinch each of salt and pepper.
3. Cut up the pork: Insert a knife into the tenderloin 2/3 of the way down, parallel to the cutting board. Begin slicing the pork lengthwise, pulling the meat back with your other hand until it opens into a flat piece of uniform thickness. Season the tenderloin with salt and pepper, brush the top with vegetable oil, and sprinkle with mushrooms. Roll the tenderloin and tie with kitchen string every 2.5 cm along the entire length. Season with salt and pepper.
4. Fit a rack in a large roasting pan. Heat the remaining 2 tablespoons olive oil in a large skillet over medium-high heat. Place the pork loin, fat side down, and cook until browned, about 3 minutes. Continue cooking, turning, until browned on all sides, another 1 to 2 minutes. Transfer the pork, seam side down, to the rack in the roasting pan. Roast on the bottom rack of the oven until an instant-read thermometer inserted into the thickest part of the meat (not the stuffing) registers 135°F (57°C), 1 hour to 1 hour 15 minutes. Transfer the pork loin on the rack to a cutting board, cover with foil, and let rest for 30 minutes.
5. Meanwhile, skim off any excess fat from the liquid remaining in the roasting pan and add the sherry. Place the roasting pan over two burners on the stovetop and heat over medium-high heat. Add the thyme and rosemary sprigs and cook, scraping up any browned bits with a wooden spoon and stirring, until the liquid has reduced by about half, 1 minute. Transfer to a small saucepan, add the chicken broth, and bring to a simmer. Reduce the heat and simmer until the liquid has reduced slightly, 4 to 5 minutes. Stir in the butter and season with salt. Strain the sauce through a fine-mesh sieve.
6. Place the roll on a cutting board and remove the string; cut into 1 cm thick slices. Transfer to a platter and serve with the sauce.