Preheat oven to 450 degrees with rack in center. Heat a large cast-iron skillet over medium-high heat until very hot. Rub lamb with oil, and season with salt and pepper. Place in skillet, and sear until golden brown all over (including ends), about 3 minutes per side. Place on a baking sheet. Let stand until cool, about 30 minutes.
In a small bowl, combine breadcrumbs, rosemary, garlic, parsley, 1/4 teaspoon salt, and 1/2 teaspoon pepper. Brush lamb with 2 tablespoons Dijon, making sure the entire surface is covered. Pat seasoned breadcrumbs over rack (reserve any remaining breadcrumbs for another use), covering Dijon in an even layer. Return to baking sheet, and roast until a thermometer inserted in the thickest part of the meat registers 130 degrees, 20 to 25 minutes. Let stand 5 minutes before carving into individual chops.