2) Strain into two Champagne flutes. Top each drink with 45ml of Champagne and garnish with the apple.
For the homemade grenadine:
1) Put the pomegranate juice in a small saucepan and bring to a boil over a high heat.
2) Reduce the heat to a gentle simmer and continue to cook until the liquid is reduced by half. Stir in the sugar to dissolve thoroughly, and simmer to thicken slightly. Cool. Cover and refrigerate for up to 2 weeks.