Preheat oven to 375°F (190°C).
Pat the pork medallions dry with paper towels. Brush each piece with Dijon mustard on all sides.
In a mixing bowl, combine panko breadcrumbs, parsley, thyme, rosemary, garlic, salt, and black pepper.
Press each pork medallion into the breadcrumb mixture, ensuring an even coating.
Heat olive oil in a skillet over medium-high heat. Sear the pork medallions for 2 minutes per side until golden brown.
Transfer to a baking sheet and bake for 10 minutes until fully cooked (internal temperature of 145°F/63°C).
Remove from oven and let rest for 5 minutes before serving.