Press each tenderloin piece into 1 inch thickmedallion; sprinkle surfaces with lemon pepper.
Melt butter in large heavy skillet over medium heat. Add medallions; cook 3 to 4 minutes on each side. Remove pork to serving platter; keep warm.
Stir lemon juice, worcestershire sauce and mustard into pan juices in skillet. Cook, stirring, until heated through. Poursauce over medallions; sprinkle with chopped chives.
Garnish with whole chives or a bit of parsley.
Serve with vegetables.