Rainbow Rum Smash From New York City's Rainbow Room. Ice 1/3 cup strawberry purée, unsweetened 1 cup fresh orange juice 1/3 cup Barbados or Jamaican rum 2 splashes soda water 2 sprigs mint Fill two highball glasses with ice. In a measuring cup, combine the purée, orange juice and rum. Stir well and pour over the ice in each glass. Add soda water; garnish with mint and serve.