Using the tip of a sharp paring knife, score the duck skin in a crosshatch pattern. Sprinkle both sides of the duck with salt. Place, skin-side down, in a large cast-iron or ovenproof skillet over medium heat. Cook, undisturbed, until some of the fat is rendered and the skin is golden brown, about 8 minutes. Transfer the duck to a clean plate and carefully pour out the fat from the pan. Return the duck to the pan, skin-side up, and brush with the honey mixture. Transfer the pan to the oven.