Add butterfly pea flowers to hot water and allow to steep for five minutes. Drain, and transfer pea tea to ice cube trays. Freeze until solid.
Crush in a blender to create shards/chunks of ice and store in freezer.
Fill a glass three-quarters up with regular crushed ice, and top with blue ice. Pour lime juice, then vodka, then ginger beer over ice and watch the colours transform. Top with additional blue ice before serving.