Get prepped: Take the lamb out of the refrigerator 30 minutes before cooking. Preheat your oven to 375°F (190°C). Season lamb generously with salt and pepper. (Seriously, don't skimp here.)
Make the herb crust: In a bowl, mix breadcrumbs, chopped herbs, garlic, 3 tablespoons olive oil, melted butter, and a pinch of salt and pepper. It should look like green, fragrant wet sand. If it's too dry, add a touch more oil.
Sear the lamb: Heat a large pan over high heat. Add a splash of oil and sear the lamb racks on all sides until golden brown (about 2-3 minutes per side). This isn't cooking it through – we're just building flavor here, people!
Apply your mustard mask: Let the seared racks cool slightly, then coat the meaty parts with Dijon mustard. Think of it as sunscreen for your lamb – complete coverage is key.
Add the herb crust: Press the herb mixture firmly onto the mustard-coated parts. Don't be shy – really pack it on there.
Roast to perfection: Place the racks in your roasting pan, crust side up, bones curving downward. Roast for 25-30 minutes for medium-rare (internal temperature of 125°F-130°F).
Rest (both you and the lamb): Remove from oven, tent loosely with foil, and let rest for 10 minutes. This is non-negotiable unless you enjoy lamb juice flooding your cutting board instead of staying in the meat.
Carve and serve: Cut between the bones to separate into individual chops and arrange artfully on plates like the culinary genius you are.