* 3/4 cup fresh lime juice (5-6 limes)
  * 1 cup sugar
  * 1/3 cup light corn syrup
  * 1 medium seedless cucumber, peeled and chopped (~2 cups)

Grate the zest from two of the limes and scrape into a food processor. Juice the limes and add 3/4 cup. Add sugar, corn syrup, cucumber, and 1 1/3 cup water. Process until smooth. Strain into the ice cream maker and process according to directions.

source: Fiesta at Rick's - Rick Bayless