Wash and clean the cucumber and cut it in half crosswise. Cut 1 half lengthwise into long, wafer-thin slices with a peeler. Cut the other half into round slices with a knife. Wash the mint, shake dry and roughly pluck the leaves.
Rinse lime and orange hot. Cut lime into slices. Use a knife to cut the orange peel very thinly into strips from the orange.
Pour gin into the bowl. Add cucumber, mint, lime and orange peel and let it stand for about 5 minutes. Then remove orange peel. Fill up punch with tonic. Prepare glasses filled with crushed ice or ice cubes and serve the punch immediately. Let the evening begin!