This turned out quite tasty indeed, will make again for sure. I adapted it from this:
http://www.food.com/recipe/pork-tenderloin-stuffed-with-brie-and-mushrooms-410227
4 medium to large yellow flesh potatoes, cut in 1/2" thick chunks
12 oz. pork tenderloin (after trimming)
2 T. butter
1/2 tsp. bottled minced garlic
1 shallot, chopped (used food processor)
12 oz. button mushroom, sliced (food processor)
1 c. (slightly over 1 oz.) baby spinach
2 splashes red wine (used Alamos Argentinian Malbec)
4 3/4 oz. Brie (prior to rind removal)
1/4 Granny Smith apple, chopped (in food processor, with walnuts)
2 T. walnuts, toasted, chopped (above)
salt, pepper, dried thyme--to taste
olive oil
1. Place cut potatoes in microwave safe container and cover. Microwave on high for 8 minutes. Drizzle with olive oil, season with salt, pepper, and dried thyme--to taste, and toss to combine.
2. Meanwhile, butterfly tenderloin lengthwise, set aside.
3. Heat oven to 375°F.
4. Melt butter in skillet (used cast iron, obviously) over medium heat and add mushrooms.
5. Cook mushrooms for a few minutes, until somewhat softened. Add shallot and garlic. Cook until liquid has nearly disappeared/evaporated.
6. Add baby spinach and cook briefly (it will quickly begin to reduce).
7. Splash in red wine and cook for around 1 minute.
8. Remove from heat and add Brie, apple, walnut, and seasonings. Stir until Brie has melted and well combined.
9. Spread enough mixture over the tenderloin to cover it entirely; leave remaining mixture in pan.
10. Fold tenderloin over to enclose the filling. Secure with butcher string.
11. Place tenderloin in middle of pan. Add potatoes to surround tenderloin.
12. Bake for around 40 minutes, or until meat thermometer registers 155°F.
13. Let it rest for 5 minutes. Remove the strings, plate it up and enjoy!
