1/2 cup fresh lime juice
3/4 cup sugar
1 cup water
1/4 teaspoon salt
1 pound chopped English cucumber (about 1 cucumber)
Combine first 5 ingredients in a small saucepan over medium heat; bring to a boil. Cook 1 minute; remove from heat; let stand 10 minutes. Place juice mixture and cucumber in a blender; process until smooth. Cool completely. Pour mixture into an 11 x 7inch baking dish. Cover and freeze for 45 minutes; scrape with a fork. Freeze. Scrape mixture every 45 minutes until completely frozen (about 3 hours). Remove from freezer; scrape with a fork until fluffy.
Adapted from Cooking Light