Total Time: 1 hr 45 mins Butterflying the pork loin, pounding it flat, and spreading it with plenty of pesto before rolling and tying helps it cook evenly while ensuring every slice is well-seasoned. Salty prosciutto and nutty Parmesan cheese melt into the filling, adding rich, savory flavor that plays perfectly with the herb-packed pesto. Searing before roasting develops a crisp, golden crust that locks in juices before the pork loin goes into the oven.