Prep the pork: Butterfly the tenderloin lengthwise (don’t cut all the way through). Open it like a book and lightly pound to even thickness. Season both sides.
Make the filling: Heat olive oil in a skillet over medium heat. Sauté mushrooms until browned and moisture cooks off. Add garlic, then spinach; cook just until wilted. Season. Stir in cream cheese and cheese; remove from heat.
Stuff & roll: Spread the filling evenly over the pork. Roll tightly and secure with twine or toothpicks.
Cook:
Oven: Sear the roll in an oven-safe skillet (2–3 min per side), then roast at 400°F for 18–22 min, until internal temp hits 145°F.
Grill: Sear over direct heat, then move to indirect heat, lid closed, until 145°F internal.
Rest & slice: Rest 5–10 minutes. Slice into medallions and serve.
Quick Tips
For a smoky twist, add a pinch of smoked paprika to the filling.
Swap in goat cheese or provolone for a different flavor.
Great sides: garlic mashed potatoes, roasted asparagus, or a crisp salad.