Chill gin on ice in a tall glass. Fill with Tonic (or Soda water). Add a Lemon wedge (squeezed and thrown in). Finally drop in the candy (originally made with %?cherry certs%? but other candies will do. %?Scotch mints%? add a nice Christmas twist). As the candy dissolves the drink slowly sweetens, the candy also forms pretty bubbles in the tonic water.
Serve in a Highball Glass