1/3 cup each fresh cilantro leaves, mint leaves, oregano leaves and thyme leaves
1/3 cup coarsely chopped fresh chives
1/3 cup chopped shallots
2 garlic cloves, crushed
3 tablespoons grated lemon zest
1/2 cup lemon juice
2 tablespoons Dijon mustard
3/4 teaspoon salt
1/2 teaspoon pepper
1/3 cup olive oil
Mix rosemary, pepper and salt; rub over lamb. Refrigerate, covered, 8 hours or overnight.
Preheat oven to 375°. Place lamb in a shallow roasting pan, fat side up; drizzle with oil.
Roast 35-45 minutes or until meat reaches desired doneness (for medium-rare, a thermometer should read 135°; medium, 140°; medium-well, 145°). Remove lamb from oven; tent with foil. Let stand 10 minutes before serving.
Meanwhile, place herbs, shallots and garlic in a food processor; pulse until herbs are chopped. Add lemon zest, lemon juice, mustard, salt and pepper; process until blended. Continue processing while gradually adding oil in a steady stream. Serve lamb with sauce.