Preheat oven to 400 degrees.
Butterfly the pork and open like a book. Rub 2 Tbsp. olive oil inside the pork. Add at least 1 tsp. of Kosher salt and 1/4 tsp. freshly ground black pepper.
Add 1 1/2 cups of the pistachio prune stuffing inside the pork. Gently bring the pork together.
Tie the pork with kitchen string.
Stretch about 5 slices of bacon; enough to completely wrap the pork loin. Wrap the bacon around the loin tucking in ends of bacon as you wrap.
Top with the remaining 1/2 cup of pistachio prune stuffing. Drizzle 2 more Tbsp. olive oil over the top. Place 5 sprigs of rosemary on top of the loin. Halfway through roasting, check to see if the pork looks dry. If it does add another Tbsp. of olive oil.
Place in the hot oven for 10 minutes. Reduce heat to 350 degrees and roast another 45-60 minutes until an internal temp of 145 is reached.
Rest, tented under foil for 10 minutes. Remove all kitchen string and then slice into thick 1 inch slices.