1. Preheat oven to 450°.
2. Rub mustard evenly over pork medallions. Combine panko, thyme, parsley, salt, and pepper in a large bowl. Dredge pork in panko mixture. Heat a large ovenproof skillet over medium-high heat. Add oil to pan; swirl to coat. Add pork; sauté 2 minutes or until golden brown. Turn pork. Place skillet in oven; bake at 450° for 8 minutes or until pork reaches 145°. Let stand 3 minutes.