2 oz of Gin
1 tbsp of port
1 tsp of water
carbonated water (or sparkling water)
nutmeg
1/2 tsp of powdered sugar (or sugar)
Dissolve powdered sugar in water and add gin. Pour into a highball glass over 2 ice cubes. Fill with carbonated water and stir. Float port on top, sprinkle lightly with nutmeg, and serve.