1The night before you plan to serve, cream together the butter, garlic, freshly ground black pepper, a couple big pinches of salt (at least 2 tsp), and lemon juice.
2Spread over rolled lamb shoulder, coating completely.
3Let stand in the refrigerator overnight until you are ready to roast.
4Position rack in middle to lower third of oven. Preheat oven to 425℉.
5Place lamb on a roasting rack. Roast until internal temperature reached 130℉ for medium. Transfer to a cutting board, cover with foil, and let stand for 10 min.