In a small saucepan on medium high heat, make a simple syrup by heating sugar and water until the sugar has completely dissolved. Remove from heat and let cool. Mix in the lemon juice and zest. Chill, either in the refrigerator, or by placing in a metal bowl over an ice bath.
2 Once the mixture has thoroughly chilled, freeze in your ice cream maker according to the manufacturer's instructions. If you don't have an ice cream maker, you can pour the mixture into a shallow pan and freeze in your freezer until semi-solid. Then take a fork and fluff it up, returning it the the freezer to freeze firm. Then put in a food-processor or blender to process until smooth.
Place sorbet in an airtight container and freeze until ready to serve.
3 Scoop out preferably with a melon-baller. Garnish with mint. Makes 2 1/2 cups.