Make the cranberry reduction 

• Add cranberries, sugar, and water to a small saucepan.
• Simmer over low heat for about 5 minutes, stirring occasionally.
• You’re looking for cranberries that burst open and a sauce that turns thick (similar to cranberry sauce).
• Remove from heat and let it cool (warm sauce melts ice and kills fizz).

Assemble 

• Add mint and lime juice to each glass.
• Muddle gently, just enough to release the mint aroma without shredding the leaves.
• Pour in the pomegranate juice.
• Add 1–2 spoonfuls of the cooled cranberry reduction (start small, then adjust).
• Give it a quick stir to distribute the flavour.

Serve

• Add ice right before serving.
• Top up with cold sparkling water, pouring gently to keep the bubbles.
• Taste and tweak.
• Garnish with mint, lime wedges, and a few cranberries or pomegranate arils.