Preparation Grind herbs, zest, juice, and 1 teaspoon coarse salt to a paste with a mortar and pestle. Transfer to a bowl and add oil in a slow stream, whisking until emulsified. Season with salt and pepper. Pat lamb dry and season with kosher salt and pepper. Heat a lightly oiled well-seasoned ridged grill pan over moderately high heat until hot but not smoking, then grill lamb, turning once, about 4 minutes on each side for medium-rare. Serve sauce spooned over lamb.
Preparation Grind herbs, zest, juice, and 1 teaspoon coarse salt to a paste with a mortar and pestle. Transfer to a bowl and add oil in a slow stream, whisking until emulsified. Season with salt and pepper. Pat lamb dry and season with kosher salt and pepper. Heat a lightly oiled well-seasoned ridged grill pan over moderately high heat until hot but not smoking, then grill lamb, turning once, about 4 minutes on each side for medium-rare. Serve sauce spooned over lamb.