Get Ready: Preheat your oven to 400°F (200°C). Let your lamb sit out of the fridge for 20-30 minutes to reach room temperature. Gently pat the lamb completely dry with paper towels. Season all sides generously with 1 teaspoon salt, ½ teaspoon pepper, and 1 tablespoon olive oil.
Sear for Sizzle: Heat a cast-iron skillet (or a heavy-bottomed oven-safe pan) over medium-high heat for about 2 minutes until nice and hot. Carefully place the seasoned lamb into the skillet and sear each side until beautifully browned, about 3-4 minutes total. Once seared, move the lamb to a plate and loosely cover it with foil.
Whip Up the Herb Crust: In a mixing bowl, combine the Panko breadcrumbs, finely chopped parsley, 2 tablespoons olive oil, minced garlic, 1 teaspoon salt, and 1 teaspoon pepper. Mix everything together until well combined. Spread this mixture out on a shallow plate.
Coat and Conquer: Take your seared lamb and generously brush all sides with the Dijon mustard. Then, press the lamb firmly into the breadcrumb mixture on the shallow plate, ensuring an even coating.
Roast to Perfection: Place the coated lamb back into your hot cast-iron skillet or onto a baking sheet lined with aluminum foil. To keep the bone tips from burning, you can cover them with small pieces of foil. Roast in your preheated 400°F (200°C) oven for 25-30 minutes. For medium-rare, aim for an internal temperature of 135°F (60°C), or 140°F (60°C) for medium, using a meat thermometer.
Rest and Relish: Once cooked to your liking, remove the lamb from the oven and loosely tent it with foil again. Let it rest undisturbed for 15 minutes to allow juices to redistribute.
Slice and Serve: Finally, slice the rack of lamb between the ribs into individual chops. Serve immediately and enjoy your impressive, healthy, and easy holiday meal!