Allow lamb to rest at room temperature for 1 to 2 hours
Preheat oven to 450 F
Place lamb fat side up in a large roasting pan
Rub well with olive oil, then liberally salt and pepper
Roast for 10 minutes
Meanwhile, combine herbs, breadcrumbs, butter, shallot, garlic, and lemon zest and pulse until a course and sandy in texture, set aside
Remove lamb from oven and press herb mixture into fat cap and sides
Return to oven and roast another 20 minutes
Remove from oven and tint lightly with foil. Rest for 15 minutes
Carve into 1- or 2-chop portions and serve