Step 1

Place butterfly pea flower, lemongrass, and ginger in medium bowl. Add boiling water and let steep for 10 minutes. Add ice water and steep for 1 hour. Strain through fine-mesh strainer into container. Stir in honey until dissolved. Refrigerate until chilled, at least 1 hour or up to 3 days.

Step 2

Fill 2 chilled glasses with ice. Add ½ cup seltzer and ½ teaspoon lime juice to each glass and stir to combine. Gently pour in ½ cup prepared butterfly pea flower tea. Top with additional ice and serve.