Put everything, except Jamaican rum, in (3 options):
- a shaker : with 4 oz (½ cup) of crushed ice and shake gently.
- a blender : with 4 oz (½ cup) of crushed ice. Blend at high speed for 2-3 seconds.
- a drink mixer : with 12 oz (1½ cups) of crushed ice and 4-6 “agitator” cubes (small ice cubes). Flash blend for 3-4 seconds.
Pour unstrained into a double old-fashioned glass (or a shark’s tooth ice shell glass). If necessary, add more crushed ice to fill.
Serve Jamaican rum separately in a shot glass, to be poured into the drink.