Combine lemon zest
, broth, oregano, lemon juice, capers, garlic and cornstarch. Set aside. Cut port into 1 inch thick slices, seasoning with salt and pepper. Heat oil in a large nonstick skillet over medium-high heat. Cook pork until browned, about 1 or 2 minutes per side. Transfer to a platter. Reduce
heat to medium, and stir in broth mixture. Cook and stir for about 1 minute. Return pork to skillet and cook 2 to 3 minutes or until juices run clear. Turn once. Spoon sauce over pork slices and serve.