Heat oven to 350 degrees F. Season pork with salt and pepper; brush with mustard. Place in roasting pan and bake until internal temperature reaches 145 degrees F, about 35 to 45 minutes. Remove from pan and let rest 10 minutes.
Stir chutney and orange juice together in small saucepan; heat on low until warmed. Slice tenderloin into medallions and serve with sauce. Top with herbs, if desired.