The Enoki mushrooms and spinach adds great flavor to this dish and the texture of the pine nuts rounds everything out nicely. I would make this recipe for a dinner party with friends.
Butterfly pork by slicing and slowly unrolling the pork trying to keep the thickness even.
In a saute pan over medium heat add a little olive oil. Add onion and saute for 2-3 minutes or until translucent. Do not brown. Add spinach and cook for 1-2 minutes until wilted and cooked down. Add salt and pepper to taste. Turn off heat and add pine nuts. Mix to incorporate and allow to cool for 5-10 minutes.
Salt and pepper both sides of pork tenderloin to taste. Add one layer of spanich, onion and pine nut mixture. Add one layer of Enoki mushrooms (bottom brown part removed.) Roll pork and use butcher twine or tooth picks to hold in place.
Preheat oven to 375 F degrees. In a saute pan over medium heat add a little olive oil. Allow to heat for about 1 minute. Carefully sear pork on all sides (1-2 minutes per side.) Place in oven and cook for 20-25 minutes until internal temperature of pork is 170 F degrees.
Remove from oven and allow to rest for 5-10 minutes. Slice into 1/2 inch circles and plate.