01 -
Set the oven to 350°F (175°C).
02 -
Heat 1 tablespoon of olive oil in a skillet over medium heat. Add the mushrooms, shallot, thyme, garlic powder, sage, black pepper, and salt. Stir and cook until the mushrooms release their liquid and the moisture evaporates, about 5–10 minutes.
03 -
Stir in the parsley and cook for another minute. Incorporate the spinach, stirring until it wilts, approximately 5 minutes. Mix in the mustard and remove from heat.
04 -
Spread the tenderloin flat on a surface. Lay the prosciutto slices across the pork and then spread the mushroom-spinach mixture evenly, leaving a 1/2-inch border near the edges.
05 -
Roll the pork tightly around the filling and tie it with kitchen twine to keep everything secure.
06 -
Heat the remaining 2 tablespoons of olive oil in a large skillet over medium heat. Brown the pork roll on all sides until golden, about 10 minutes.
07 -
Transfer the browned pork roll to a 9x13-inch baking dish. Bake it for 25–30 minutes, or until the internal temperature reads 145°F (63°C). Let it rest briefly before slicing.