Preheat the oven to 400°F (200°C).

Season the rack of lamb with salt and pepper.

In a food processor, combine parsley, rosemary, thyme, garlic, breadcrumbs, and olive oil. Pulse until finely chopped and well mixed.

Spread Dijon mustard over the meat side of the lamb, then press the herb mixture onto the mustard to form a crust.

Place the rack of lamb in a roasting pan, meat side up.

Roast in the preheated oven for about 25-30 minutes, or until the internal temperature reaches 130°F (54°C) for medium-rare.

Remove from the oven and let rest for 10 minutes before slicing.