In a small bowl, stir pomegranate juice, vinegar, oil, garlic, fresh rosemary, and salt and pepper.
Place the pork tenderloin in a freezer bag or container. Marinate pork for at least 30 minutes.
Add the olive oil to a skillet and heat over medium.
Sear the pork on all sides so it's nice and brown. Remove from heat.
Preheat oven to 400 degrees. Line a baking sheet with foil and place a wire rack on top.
Place pork onto rack and cook for 45 minutes to an hour, or until the pork is cooked through.
Allow the pork to rest about 5-10 minutes.
Slice pork and garnish with fresh rosemary sprigs and pomegranate seeds.