Pour ginger, cloves and grains of paradise in to a mortar and grind until fine texture is achieved. Set aside.
Pour water into a saucepan over medium heat, add the pineapple skin, the grounded spice, hibiscus flowers, stir and let boil for 10 minutes.
Strain, add sugar, stir and let cool off completely.
Pour into ice cube trays and freeze overnight or at least 8 hours.
Take out from the freezer and pop the frozen cubes in a blender, add vodka and blend till smooth.
Pour into serving glasses and garnish with mint leaves and lemon slices.
Hibiscus slashers ready to serve. NB://Best served chilled.