Preheat oven to 400°F. Whisk honey, soy sauce and mustard in small bowl to blend; add 2 tablespoons glaze to sauce. Sprinkle lamb with salt and pepper. Place on baking sheet. Brush each rack with some of remaining glaze. Roast until thermometer inserted into center of lamb registers 130°F, brushing often with more glaze, about 35 minutes.