Bring the water and sugar to a boil in a small saucepan, remove from the heat, and cool. Combine the syrup with the lemon and zest and pour into the bowl of an ice cream machine. Freeze according to the manufacturer's instructions. After the sorbet is made, transfer to an airtight container. Cover tightly and freeze until ready to serve.
Note: If you are concerned if the oils or other ingredients in these recipes are suitable for Passover, seek non-dairy substitutes or ingredients that are certified kosher for Passover.