01 - Preheat oven to 400°F.
02 - Pat the lamb rack dry. Rub all over with 1 tbsp olive oil, salt, and pepper.
03 - Heat a large ovenproof skillet over medium-high heat. Sear the lamb rack, fat side down, for 2–3 minutes until browned. Turn and sear other sides for 1–2 minutes each. Remove from heat.
04 - In a bowl, combine breadcrumbs, parsley, rosemary, thyme, garlic, Parmesan, lemon zest, and 2 tbsp olive oil. Mix until the crumbs are evenly moistened.
05 - Brush the seared lamb with Dijon mustard.
06 - Press the herb crumb mixture firmly onto the fat side of the rack.
07 - Place lamb in the skillet or on a baking tray. Roast in the oven for 15–20 minutes for medium-rare (internal temperature of 135°F).
08 - Remove from oven, tent loosely with foil, and let rest for 10 minutes.
09 - Slice between the bones and serve.