This is a great recipe for a simple yet special party drink. Simple because there aren't many ingredients. Special because limes are so expensive (in NZ they usually are anyway). If you want you could exchange them for lemons.
Lime concentrate or cordial
First get out your largest jug or punch bowl
Zest and juice 5-6 limes (depending on the size of your container)
Slice in the remaining 5-6 limes
Add 200ml lime concentrate/cordial
Top up with soda water