Slice down the center of the pork loin lengthwise with a sharp knife, leaving at least 1 inch uncut to hold the meat together. Make slow, long cuts until the roast opens like a book. Then, use a meat tenderized to hammer the piece of meat until it's mostly flat before filling and rolling. After cooking, use a long carving knife or serrated knife to gently trim slices of the stuffed pork loin for serving.