Cook's Note: Honey simple syrup is made by heating 3 parts honey with 1 part water until the honey is dissolved.
Mash the lemon pieces in a cocktail shaker using a muddler until broken down and the juice is released. Add the gin, honey simple syrup and salt and fill with ice. Cover and shake vigorously until very cold.
Rub the rim of a champagne coupe (short-stemmed "bowl" champagne glass) or martini glass with the lemon wedge and coat it with ground long pepper, shaking off the excess. Strain the drink into the rimmed glass and sprinkle the peppercorns over the top. Serve immediately.