In a blender, blend together ¾ of the strawberries, balsamic vinegar, olive oil, salt, pepper, rosemary, and lemon juice. Place tenderloin and marinade into a large resealable bag or a shallow baking dish, coating all sides. Refrigerate minimum 1 hour up to overnight.
Preheat oven to 375° F. Heat grill pan on medium high heat. Once it’s hot, remove pork from marinade and cook it on the grill pan for 12 minutes, turning every 3 minutes. Place the pork on a baking sheet and finish cooking it in the oven until the internal temperature of the pork reaches 140° F – about 10 minutes. Remove from oven and let rest for 5-10 minutes.
While the pork is in the oven, pour the rest of the marinade into a saucepan over medium heat. Add the shallots, wine and sugar. Bring to a simmer. Continue to simmer until wine has reduced and strawberries have thickened, about 10 minutes.
To serve, slice loin in to ¾ inch slices, then plate topping with strawberry sauce. Garnish with fresh strawberries and rosemary.