In small sauce pan, mix water, sugar and mint. Bring to boil over high heat stirring to dissolve sugar. Cover and reduce heat to low and simmer 5 minutes. Turn off heat and stir in the zest of the lemon. Cover and let cool to room temperature. Strain through fine mesh strainer, add lemon and orange juice and refrigerate until cold.
Freeze in ice cream maker. Transfer to a container with a tight fitting lid. Ripen in freezer several hours. This should not be frozen too hard but it should also not be served "slushy". Best served in small bowls or glasses that have been cooled in the freezer.