1. In a punchbowl or jug combine chilled pineapple juice and orange juice and stir in aromatic bitters.
2. Among 4 chilled glasses divide the mixed drink, tip each glass and slowly pour ginger ale down side to fill.
3. With a scoop of pineapple sherbet top each serving.
4. If desired, on glass straws thread fresh fruit (strawberries, pineapple chunks, melon balls) for kabob stirrers.
5. Garnish each appetizer with a sprig of fresh mint, if desired and serve.